I have gotten the same thing you have. It seems to be intermittent, but when it occurs, it seems to be cleared up if you close VFP, delete .FXP, clear programs, reboot, take the blood of a live chicken, human sacrifice in a volcano, and then finally offer up your first born. Unfortunately, because of the last item, you can only accomplish this once.

If anyone know a 100% foolproof way of fixing this, please let me know, also. Thanks