Thank you for your post.
There have been no reports of FileMaker Pro 10 crashing on a Vista machine either as stand alone or on a network.
Since it sounds like FileMaker Pro 10 is the only application crashing, try uninstalling and reinstalling FileMaker Pro 10. If that doesn't work, then run msconfig and stop all non-Microsoft Services.
Thanks. I'm not due at client's until next week. I'll try your suggestions then. Appreciate the help.