Need more info:
- does the form crash in Win95 when run by itself?

I can't try it because I only have access to a Win NT system for developping. The Win95 system is a client from our company.

- what is the error message (if any)

sometimes no error message, sometimes "Cannot find X.X or one of it component"

- when you say "hang", can you still reboot with cntl-al-del

Yes

Narrow down the code to the line or small block of code that can reproduce this behaviour consistently.

Unfortunateley it is only this:
-DO FORM name_of_the_form