Cannot receive window message from child popup - Winforms

I created Scintilla Popup for textbox to show autocomplete :

 this.hWnd = CreateWindowEx(
                0, "Scintilla", "",
                WS_CHILD | WS_VISIBLE | WS_TABSTOP | WS_CLIPCHILDREN | 0x00002000,
                x, y, textbox1.ClientSize.Width, textbox1.ClientSize.Height, textbox1.Handle, (IntPtr)0, (IntPtr)0, (IntPtr)0);

and in custom textbox, i overriden WndProc :

  protected override void WndProc(ref Message m)
{
}

I build project in x86, and each time i call "SendMessage", the autocomplete showed on textbox and WndProc called. But when i build project in x64, only autocomplete showed and WndProc not called. Please, help me ??

Thanks.

EDIT: Added code below, previously posted by OP as an answer

@o_weisman, this is my custom textbox :

public partial class ScintillaControl : TextBox
    {

        ScintillaWrapper sw = null;
        public ScintillaWrapper Scintilla
        {
            get { return this.sw; }
        }

        LanguageType languageType = LanguageType.CS;
        public LanguageType LanguageType
        {
            get { return languageType; }
            set { languageType = value; }
        }

        bool useBuiltInPopupMenu = true;
        public bool UseBuiltInPopupMenu
        {
            get { return useBuiltInPopupMenu; }
            set { useBuiltInPopupMenu = value; }
        }

        bool _notModified = false;
        public bool NotModified
        {
            get { return _notModified; }
            set { _notModified = value; }
        }

        public ScintillaControl()
        {
            this.Multiline = true;
            this.AcceptsTab = true;
           // this.ShortcutsEnabled = true;

        }


        protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {
            const int WM_KEYDOWN = 0x100;
            var keyCode = (Keys)(msg.WParam.ToInt32() &
                                  Convert.ToInt32(Keys.KeyCode));
            if ((msg.Msg == WM_KEYDOWN && keyCode == Keys.A)
                && (ModifierKeys == Keys.Control)
          )
            {
                this.SelectAll();
                return true;
            }
            return base.ProcessCmdKey(ref msg, keyData);
        }
        public new bool Enabled
        {
            get { return base.Enabled; }
            set
            {
                base.Enabled = value;
                Color bkColor = (value ? Color.White : System.Drawing.SystemColors.ControlLight);
                if (this.sw != null)
                    this.sw.SetWindowBackground(bkColor);
            }
        }

        //[DllImport("User32.dll")]
        //private static extern int GetAsyncKeyState(int vKey);

        private bool DetectCtrlPressed()
        {
            Keyboard kb = new Keyboard();
            return kb.CtrlKeyDown;

            //int detectCtrlPressed = GetAsyncKeyState(0x11);
            //return (detectCtrlPressed == 32768 || detectCtrlPressed == -32767);
        }

        private bool DetectCtrlShiftPressed()
        {
            Keyboard kb = new Keyboard();
            return kb.CtrlKeyDown && kb.ShiftKeyDown;
        }

        private bool DetectShiftPressed()
        {
            Keyboard kb = new Keyboard();
            return kb.ShiftKeyDown;
        }

        protected override void OnCreateControl()
        {
            base.OnCreateControl();
            CreateScintillaControl();
        }


        public void CreateScintillaControl()
        {
            if (this.sw != null)
                return;
            try
            {
                this.sw = new ScintillaWrapper();
                this.sw.MapForm = this.mapForm;
                this.sw.ParentControl = this;
                this.sw._CreateWindow(0, 0, this.ClientSize.Width, this.ClientSize.Height, this, languageType);
                this.sw._DisableBuiltInPopupMenu(this.useBuiltInPopupMenu);

                //Trace.Listeners.Add(new TextWriterTraceListener("C:\\trace.txt"));
            }
            catch (Exception ex)
            {
                MessageBox.Show("error while creating scintilla wrapper, ex: " + ex.ToString());
            }
        }

        protected override void OnSizeChanged(EventArgs e)
        {
            base.OnSizeChanged(e);

            if (this.sw != null)
                this.sw._ChangeSize(new Point(0, 0), new Size(this.ClientSize.Width, this.ClientSize.Height));
        }

        public delegate void ScintillaDoubleClick(int lineNumber, string content);
        public event ScintillaDoubleClick OnScintillaDoubleClick = null;
        private void DoOnScintillaDoubleClick(int lineNumber, string content)
        {
            if (this.OnScintillaDoubleClick != null)
                this.OnScintillaDoubleClick(lineNumber, content);
        }

        public delegate void TrackPopupMenu(Point p);
        public event TrackPopupMenu OnTrackPopupMenu = null;
        private void DoOnTrackPopupMenu(Point p)
        {

            if (this.OnTrackPopupMenu != null)
                this.OnTrackPopupMenu(p);
        }

        public delegate void CodeChanged(ScintillaControl control);
        public event CodeChanged OnCodeChanged = null;
        private void DoOnCodeChanged(ScintillaControl control)
        {

            if (this.OnCodeChanged != null)
                this.OnCodeChanged(control);
        }

        public delegate void SelectionChanged(bool isChanged);
        public event SelectionChanged OnSelectionChanged = null;
        private void DoOnSelectionChanged(bool isChanged)
        {

            if (this.OnSelectionChanged != null)
                this.OnSelectionChanged(isChanged);
        }

        public delegate void ModifyCode();
        public event ModifyCode OnModifyCode = null;
        private void DoOnModifyCode()
        {

            this.sw.ReDrawLineNumberPanel();
            if (this.OnModifyCode != null)
                this.OnModifyCode();
        }

        public delegate void UIChangedDelegate();
        public event UIChangedDelegate OnUIChanged = null;



        protected override void OnGotFocus(EventArgs e)
        {

            base.OnGotFocus(e);
            this.sw._SetFocus();


        }


        private const int WM_PASTE = 0x0302;
        protected override void WndProc(ref Message m)
        {
            if (m.Msg == ScintillaWrapper.SCK_DELETE)
            {
                this.DoOnCodeChanged(this);
            }
            else if (m.Msg == 0x0111 /*WM_COMMAND*/ && this.sw != null)
            {
                if (m.LParam == this.sw._HWnd)
                {
                    int value = m.WParam.ToInt32();
                    if ((value >> 16) == 512)
                    {
                        this.Select();
                        //this.sw._SetFocus();
                    }
                }
            }

            else if (m.Msg == 0x007B /*WM_CONTEXTMENU*/ && this.useBuiltInPopupMenu == false)
            {
                int value = m.LParam.ToInt32();
                // tach value lam low word va high word
                int lowWord = value & 0x0000FFFF;
                int highWord = value >> 16;
                Point p = new Point(lowWord, highWord);
                this.Select();
                //this.sw._SetFocus();
                this.DoOnTrackPopupMenu(p);
                return;
            }
            else if (m.Msg == 0x004E /*WM_NOTIFY*/ && this.sw != null)
            {
                this.ProcessNotify(m);
            }

            base.WndProc(ref m);
        }

        CalltipInfo _currentCallTip = null;
        bool _hasSelect = false;
        bool _hasSelect2 = false;
        SCNotification tmpNotify;

        private void ProcessNotify(Message m)
        {
            bool is64bit = Util.Utility.OtherFunction.IsOS64bit;
            SCNotification notify;
            uint code = 0;

            if (is64bit)
            {
                IntPtr pDevicePathName = new IntPtr(m.LParam.ToInt64() + IntPtr.Size);
                notify = (SCNotification)Marshal.PtrToStructure(pDevicePathName, typeof(SCNotification));
                code = notify.idFrom;
            }
            else
            {
                notify = (SCNotification)Marshal.PtrToStructure(m.LParam, typeof(SCNotification));
                code = notify.code;
            }
            //if (notify.hwndFrom != this.sw._HWnd)
            //    return;

            switch (code)//(notify.code)
            {

                case ScintillaWrapper.SCN_MARGINCLICK:
                    if (notify.margin == ScintillaWrapper.MARGIN_SCRIPT_FOLD_INDEX) this.Scintilla._Fold(notify.position);
                    else if (notify.margin == 2)
                    {
                        this.Scintilla._ToggleBreakPoint(notify.position);
                    }
                    break;

                case ScintillaWrapper.SCN_CHARADDED:
                    if (this.sw.GetReadOnly()) break;
                    if (this.sw._CharAdd(notify.ch, this.DetectCtrlPressed(), this.DetectShiftPressed()))
                        break;
                    this.DoOnModifyCode();
                    this.OnTextChanged(new EventArgs());
                    break;

                case ScintillaWrapper.SCN_AUTOCSELECTION:
                    _hasSelect = true;
                    //    string s = Marshal.PtrToStringAnsi(notify.text);
                    //    this.Scintilla._AutoCompleteSelected(notify.lParam.ToInt32(), s);
                    break;

                case ScintillaWrapper.SCN_CALLTIPCLICK:
                    this.Scintilla._CalltipClicked(notify.position);
                    break;

                case ScintillaWrapper.SCN_DOUBLECLICK:
                    int lineNumber = this.sw.GetCurrentLine();
                    string content = this.sw.GetLineContent(lineNumber);
                    this.DoOnScintillaDoubleClick(lineNumber, content);
                    break;

                case ScintillaWrapper.SCN_SAVEPOINTLEFT:
                    this.DoOnCodeChanged(this);
                    break;

                case ScintillaWrapper.SCN_DWELLSTART:
                    this.sw._MouseOver(notify.position);
                    break;

                case ScintillaWrapper.SCN_DWELLEND:
                    this.sw._MouseOut();
                    break;

                case ScintillaWrapper.SCN_UPDATEUI:
                    this.sw._CursorChanged();

                    if (this.sw.GetText() != "")
                    {

                        this.getCurrentColPos();
                    }
                    if (this.OnUIChanged != null)
                        OnUIChanged();

                    //this.DoOnModifyCode();
                    break;

                case ScintillaWrapper.SCN_MODIFIED:

                    if (notify.modificationType == 2064 && notify.length == 1 && _notModified == false)
                    {
                        this.DoOnModifyCode();
                        this.OnTextChanged(new EventArgs());
                    }
                    else if ((notify.modificationType == 1040 || notify.modificationType == 2064) && !_notModified)
                    {
                        this.DoOnModifyCode();
                    }

                    //DVC 2/4/10
                    if (!ReferencesHolder.IsSearching)
                    {
                        if (this.Scintilla._GetBit(1, notify.modificationType))//Delete text event
                        {
                            this.Scintilla._CheckBreakPoint(notify.position);
                        }
                    }
                    //End 

                    if (_hasSelect && ((notify.modificationType & ScintillaWrapper.SC_MOD_INSERTTEXT) != 0))
                    {
                        _hasSelect2 = true;
                        _hasSelect = false;
                    }

                    break;

                case ScintillaWrapper.SCN_SELECT_AC_ITEM:
                    string s = Marshal.PtrToStringAnsi(notify.text);
                    _currentCallTip = this.sw.ShowToolTip(new Point(notify.x, notify.y), notify.position, notify.margin, notify.message, s);
                    tmpNotify = notify;
                    break;

                case ScintillaWrapper.SCN_CLOSE_AC_LIST:
                    this.sw.HideToolTip();
                    break;

                //case ScintillaWrapper.SCN_PAINTED:
                //    break;

                case ScintillaWrapper.SCK_DELETE:
                    this.DoOnModifyCode();
                    break;

                default:
                    if (_hasSelect2)
                    {
                        AddParenthesisIfNeeded();
                        _hasSelect2 = false;

                        sw.InsertText(" ");
                        sw.AutoCompleteProcess.InitAutoComplete(32, sw.GetCurrentPos(), sw.GetText(), false, true);

                        //string s1 = Marshal.PtrToStringAnsi(tmpNotify.text);
                        //this.sw.ShowToolTip(new Point(tmpNotify.x, tmpNotify.y), tmpNotify.position, tmpNotify.margin, tmpNotify.message, s1);
                    }

                    bool isChanged = this.sw.HasSelection();
                    this.DoOnSelectionChanged(isChanged);
                    //this.DoOnModifyCode();
                    break;
            }
        }
        public void getCurrentColPos()
        {
            Control parent = this.Parent;
            while (!(parent == null) && !(parent.Name == "Check Output"))
            {
                parent = parent.Parent;
            }


            if (parent != null)
            {
                var lengthOfAlllineBefore = 0;
                var currentPos = 0;
                if (this.sw.GetCurrentLine() > 0)
                {
                    for (int i = 0; i < this.sw.GetCurrentLine(); i++)
                    {
                        lengthOfAlllineBefore += this.sw.GetLineContent(i).Length;
                    }
                    currentPos = this.sw.GetCurrentPos() - lengthOfAlllineBefore;
                }
                else
                {
                    currentPos = this.sw.GetCurrentPos();
                }
                if (parent.Controls["panel2"] != null)
                {
                    parent.Controls["panel2"].Controls["lblCurrentColumnPosition"].Text =
                     string.Format("Col:{0}", currentPos);
                }

            }
            // this.sw.get
        }

        private void AddParenthesisIfNeeded()
        {
            try
            {
                string text = sw.GetText();
                sw.AutoCompleteProcess.DocumentString = text;
                _currentCallTip = sw.AutoCompleteProcess.FindCalltipVariable(sw.GetCurrentPos() - 1, text, 0);
                if (_currentCallTip == null || _currentCallTip.IsProperty)
                {

                    return;
                }
                sw.InsertText("()");
                sw.SetCurrentPos(sw.GetCurrentPos() - 1);
                sw.ClearSelection();
                _currentCallTip = null;
            }
            catch { }
        }


        public void SetSavePoint()
        {
            if (this.sw != null)
                this.sw._SetSavePoint();
        }

        public void SetReadOnly(bool readOnly)
        {
            this.Scintilla.SetReadOnly(readOnly);
        }

        public void ToggleBreakPoint()
        {
            this.Scintilla._ToggleBreakPoint();
        }

        protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);

            if (this.sw != null)
                this.sw.Dispose();

            this.OnTrackPopupMenu = null;
            this.OnCodeChanged = null;
            this.OnSelectionChanged = null;
            this.OnTrackPopupMenu = null;
        }

        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // ScintillaControl
            // 
            this.Multiline = true;
            this.ResumeLayout(false);

        }
    }