>If you don't force the record lock manually using RLOCK() to update but instead set buffering to 5 (optimistic table locking) and use tableupdate() to update, do you still receive the error?

Buffering on the table is set to 5. In the form, I am not issuing an RLOCK, just a REPLACE... statement. I was using the RLOCK manually after the error occured to try to debug.