>That continues to amaze me. I have never heard of a program that required you to roll back to ground zero before installing Service Pack n.

It's related to VFP xBase components. They do not have versions built in like EXE or DLL so VFP installer relies on Last Modified date to determine if SP updates are newer than ones on the disk. If xBase components were modified they could have later date than in SP and will not be replaced.