ORA-03111 error when i use date in querystring

I have a simple query string. I'm getting a weird database error when i use datetime in querystring and can't figure out why. Query works on oracle without error.

    Dim selectedDate As String = (Today.AddDays(-2000)).ToString("d-MMM-yyyy", CultureInfo.CreateSpecificCulture("en-US")).ToUpper()
    Dim cmd As New OracleCommand
    cmd.Connection = xConnection
    cmd.CommandType = CommandType.Text
    cmd.CommandText = "SELECT * FROM ORDER_DETAIL WHERE ORDER_TYPE='PO' AND STATUS<>'CANCEL' AND PN='XXXXXX' AND LAST_DATE_RECEIVED>TO_DATE('27-JUN-2013','DD/mm/YYYY')"
    Dim dr1 As OracleDataReader = cmd.ExecuteReader()

I think it's not related Oracle server or provider because it doesn't give an error if i remove the date part. Do you have any idea?

Exception details below:

Oracle.ManagedDataAccess.Client.OracleException
  HResult=0x80004005
  Message=ORA-03111: Break received on communication channel
  Source=Oracle Data Provider for .NET, Managed Driver
  StackTrace:
   at OracleInternal.TTC.TTCExecuteSql.ReceiveExecuteResponse(Accessor[]& defineAccessors, Accessor[] bindAccessors, Boolean bHasReturningParams, SQLMetaData& sqlMetaData, SqlStatementType statementType, Int64 noOfRowsFetchedLastTime, Int32 noOfRowsToFetch, Int32& noOfRowsFetched, Int64& queryId, Int32 longFetchSize, Int64 initialLOBFetchSize, Int64[] scnFromExecution, Boolean bAllInputBinds, Int32 arrayBindCount, DataUnmarshaller& dataUnmarshaller, MarshalBindParameterValueHelper& marshalBindParamsHelper, Int64[]& rowsAffectedByArrayBind, Boolean bDefineDone, Boolean& bMoreThanOneRowAffectedByDmlWithRetClause, List`1& implicitRSList, Boolean bLOBArrayFetchRequired)
   at OracleInternal.ServiceObjects.OracleCommandImpl.ExecuteReader(String commandText, OracleParameterCollection paramColl, CommandType commandType, OracleConnectionImpl connectionImpl, OracleDataReaderImpl& rdrImpl, Int32 longFetchSize, Int64 clientInitialLOBFS, OracleDependencyImpl orclDependencyImpl, Int64[] scnForExecution, Int64[]& scnFromExecution, OracleParameterCollection& bindByPositionParamColl, Boolean& bBindParamPresent, Int64& internalInitialLOBFS, OracleException& exceptionForArrayBindDML, OracleConnection connection, OracleLogicalTransaction& oracleLogicalTransaction, IEnumerable`1 adrianParsedStmt, Boolean isDescribeOnly, Boolean isFromEF)
   at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)
   at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader()
   at VB_TestApp.Module1.Main() in c:\users\.....

Inner Exception 1:
NetworkException: ORA-03111: Break received on communication channel

The below syntax needs to be changed slightly. The syntax in the question has a date format syntax error.

cmd.CommandText = "SELECT * FROM ORDER_DETAIL WHERE ORDER_TYPE='PO' AND STATUS<>'CANCEL' AND PN='XXXXXX' AND LAST_DATE_RECEIVED>TO_DATE('27-JUN-2013','DD/mm/YYYY')"

can be changed to standard syntax

AND LAST_DATE_RECEIVED> date '2013-06-27'"

Oracle Supports ANSI date format - Standard Docs Link