CString exception error in a DLL

I have a class in a DLL.
It is currently dynamicly linked to the MFC's.
This is a code snipet from the base class.
Everytime I try to run it I get an exception error at the line:
ConPath = "ODBC;DSN=Simply: ";
If I comment out this line the next exception error occurs at:
Filename=FOpen.GetFileName();

Seems to be the CString class (and yes I have included the header file for the CString class..:) )

Any suggestions would be appreciated..




class  CAccounts  
{
private:
     
protected:
     long NoAccounts;
     long NoTxs;    
     CTime CurrentUsingDate;
     CString ConPath;
     CString Filename;
//==================================

void CAccounts::OpendataBase()    
{
ConPath = "ODBC;DSN=Simply: ";
CFileDialog FOpen(TRUE,"*.sdb","*.sdb",OFN_HIDEREADONLY,"Simply Data |*.sdb ||");
     
     if (FOpen.DoModal()==IDOK)
     {
     Filename=FOpen.GetFileName();


     Filename = Filename.Left(13);
     ConPath=ConPath+Filename+";UID=sysadmin";