More Info:

The Fail, Revert, Requery technique has been working perfectly for another one of our clients, so we decided to investigate. We are in the process of migrating their large Clipper system to VFP, so the main SysInfo "key" table is type FOX2X by necessity - IT WORKS PERFECTLY! For testing, we changed the table to a standard VFP free table and it dies every time.

This is starting to smell like a bug ... I'll try to work up some repro code.