I still can't explain this; I know it was happening after I ran a certain routine, so I went and rebuilt that routine from scratch (threw the while thing out, imagined I was writing it for the first time - which is something we should all probably do on any program's third birthday). Now my rebel code runs fine, even though that isn't what I rebuilt.

I even reinstalled FoxPro. Thanks for everyone's help, but I think it will remain a mystery. I'm calling it a memory problem.