>>Does this happen on other, completely different computers? I'm wondering if it might be a hardware driver issue (video driver etc.).
> It happens on my development machine and on at least two machines at the client site. I doubt it is a video driver issue.
>
>>Can you post some simple repro code that other people could try?
> I'm sorry, I can't because there's tons of it and I don't know which part is relevant. I could send the frx to anyone who wants to see it but I don't think this would help because, as I pointed out, the exact same FRX exhibits different behavior in different apps on the same machine. I don't think this is an error on my part. I'm hoping someone has experience with this or something similar.

Which version and service pack of VFP are you using?

A SWAG, maybe you could try renaming your FOXUSER.* resource files. You could also try running the VFPClean.app that is available for VFP7 and higher.

If it's just one FRX that's causing trouble, maybe you could open it as a table and scan for bad characters such as CHR( 0 ).