_T("No name") wrote:

CDialog::OnEraseBkgnd(pDC);

When you call the OnEraseBkgnd base method MFC calls the DefWndProc which will fill the dialog with its associated background brush, so remove this line. Also, make sure to set the transparent style of the dialog to TRUE

as far as I know, the only difference between CMutex and CCriticalSection is that CMutex works at the kernel level and so can be used across process boundaries So why can you specify the timeout with CMutex::Lock method, but not in CCriticalSection::Lock?

CMutex mutex;
mutex.Lock( 1000 );

CCriticalSection critsec;
critsec.Lock( 1000 ); //here you will get an assertion