I have a legacy VB6 program that I am updating to Win7. This is a machine vision app, with a new DLL from a camera vendor.

I have a very simple VB6 test program that works great with the new DLL - both in the IDE, and as a compiled EXE.

When I add the updated code to my main project, the program works flawlessly when run from the IDE, but fails simple calls when compiled as an EXE.

i.e. - there is a simple function call to identify any camera devices connected to the computer. If I add a call to this function as the first line of code in the opening form, it works through the IDE, but returns an empty string when run as an EXE. Again, this works fine, with a much simpler project.

Somehow, adding additional forms, modules, and/or project components or references, breaks the EXE.

I have tried Win7 options of 'XP compatibility mode' and 'run as admin' - but nothing seems to help.

What's different between the IDE and the compiled EXE environments?

Additional possible clue: 'sometimes' when run from the IDE, I get the following error message:

"Can't create window of class wxWindowClassNR (error 0: the operation completed successfully.)"

This in itself boggles my mind: an error message, followed by a statement that the err number is 0, and no error????

Any clues to any of the above would be appreciated...