One additional thought...

If no one is aware of any obvious issues when testing/editing in VFP 7 to be run under VFP 6 my issue may simply be that VFP 7 is more stable than 6.

I say this because I noticed yesterday that a change in the modal form's INIT method that SCANned through the cursor did not reposition the record pointer correctly. This caused a C0000005 crash in VFP 6.

VFP 7, however, did not crash but gave a "Record is in use by another user" error and closed the form. Correctly repositioning the cursor's record pointer fixed the problem, at least in VFP 7.

My though is that perhaps this, or some very recent change in my code, is just handled more robustly by VFP 7.