HTTPWebRequest "PUT" error status 405 Method not allowed in IIS7

My app use HttpWebRequest "Put" method to upload file into the asp.net apps hosted in iis7. I had an error Status Code 405 Method Not Allowed. I've tried all solutions that I can found in the forum for 2 days, including removing the webDav in handlers, adding "Put" method into the handlers ( as found in http://blogs.msdn.com/b/joseph_fultz/archive/2009/07/23/enabling-the-put-verb-with-handlers-and-iis-7-0.aspx), re-register asp.net into iis. But none of the solutions work in my case.

I run Failed Request Tracing in iis, and below is the error:

MODULE_SET_RESPONSE_ERROR_STATUS
ModuleName  StaticFileModule
Notification    128
HttpStatus  405
HttpReason  Method Not Allowed
HttpSubStatus   0
ErrorCode   2147942401
ConfigExceptionInfo     
Notification    EXECUTE_REQUEST_HANDLER
ErrorCode   Incorrect function. (0x80070001)
    MODULE_SET_RESPONSE_ERROR_STATUS
Warning     

ModuleName="StaticFileModule", Notification="EXECUTE_REQUEST_HANDLER", HttpStatus="405", HttpReason="Method Not Allowed", HttpSubStatus="0", ErrorCode="Incorrect function

Any help is highly appreciated. Thanks. My asp.net apps/form was developed using Visual Studio 2008 and published in iis 7.

--------------------------------------- UPDATE

The code to handle the HttpWebRequest (PUT) is below: It took the user authentication token and verify it. After that it created a authentication ticket and response back to user.

     tokenSignature = false;

        //To capture the tokenId
        string MainString = Request.Headers.ToString();
        int FirstChr = MainString.IndexOf("*=");
        MainString = MainString.Substring(FirstChr + 2);
        int secondChr = MainString.IndexOf("%");
        tokenId = MainString.Substring(0, secondChr);


        //to Write the received encrypted token into temporary folder
        FileStream fs = new FileStream(AppsConfig.temp + tokenId, FileMode.Create);
        BinaryWriter bw = new BinaryWriter(fs);

        //Convert the listenerRequest into InputStream to write the token
        Stream InputStream = Request.InputStream;
        byte[] inData = new byte[32768];
        int bytesRead;

        while ((bytesRead = InputStream.Read(inData, 0, inData.Length)) > 0)
        {
            bw.Write(inData, 0, bytesRead);
        }

        //close the connection that is used to write the token
        bw.Close();
        fs.Close();

        //Read the temporary encrypted token (for decryption purposes)
        fin = File.OpenRead(AppsConfig.temp + tokenId);

        //To read the private key
        Stream prSignKey = File.OpenRead(AppsConfig.privateKey);
        PgpSecretKey pgpSec;
        PgpSecretKeyRingBundle ringBundle = new PgpSecretKeyRingBundle(PgpUtilities.GetDecoderStream(prSignKey));

        //Get the company key Id and passphrase
        String[] getText = new String[2];
        int no = 0;
        TextReader readFile = new StreamReader(AppsConfig.keyFile);

        do
        {
            getText[no] = readFile.ReadLine();
            no++;
        } while (no < 2);
        readFile.Close();
        long KeyId = Int64.Parse(getText[0]);
        Char[] passwd = getText[1].ToCharArray();
        //Get the private key
        pgpSec = ringBundle.GetSecretKey(KeyId);
        PgpPrivateKey pgpPrivate = pgpSec.ExtractPrivateKey(passwd);

        //Close all unnecessary connections
        InputStream.Close();
        prSignKey.Close();
        readFile.Close();

        //Call the decrypt method to decrypt the token
        decryptFile(fin, pgpPrivate, "original.xml", tokenId);

        if (tokenSignature == true)
        {
            //Create the authentication cookie and add this cookie to the httpResponse
            //This authentication cookie would be used to access the resource.aspx
            HttpCookieCollection cc = Response.Cookies;
            FormsAuthentication.SetAuthCookie(tokenId, false);
            cc = Response.Cookies;

        //remove the temporary file that was created earlier.
            File.Delete(AppsConfig.temp + tokenId);
            File.Delete(AppsConfig.temp + tokenId + ".bin");
        }
        else
        {
            Server.Transfer("~/Error.aspx?errorMessage=" + "SignatureFailed");

        }

There are a couple routes too fix this problem:

1) Uninstall WebDAV from the server entirely. You can do this from the Windows Add/Remove features app. This will require a reboot.

2) The second solution is simple. A) Go to the IIS Site and click modules. Find the WebDAV module and remove it.

Now you can still use WebDAV on your other sites and not interfere with the PUT method on this site.

B) You may need to find the correct handler mapping and add the PUT verb.