I ran my test with the 'optional' arguments defined as pythoncom.Missing and it does work now. Previously my code was working under a very old Python 1.5.2 where the 'defaultNamedNotOptArg' was defined as pythoncom.Missing in the .py file generated for the Excel 11.0 Object Library.
Evidently the more recent Pywin32 for 2.2.3 has defined these optional arguments as pythoncom.Empty and thus the error was occurring. I expect there was some rationale for changing the defaults, but it seems an 'optional' argument would want to use Missing rather than Empty. I'm not an expert by any means though, so will do what works. Thanks for pointing out the solution to my problem. -Craig _______________________________________________ Python-win32 mailing list Python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32