MorseKeyer currently does not work with COM ports above 9. It says 'Failed to open COMXX. Doesn't exist or may be in use."
The COM device name must be passed as \\.\COMxx instead of just COMxx to CreateFile; an easy fix. See: http://support.microsoft.com/kb/115831
Tested on Vista/W7 by changing the source code and recompiling with VS2008.