I can confirm that this rename locking doesn't happen in GL9.3A, and I saw this in 93B. I have already written up something for R&D to investigate. Knowing one reason why files are locked is probably all they need - it's pretty likely that if the Net Changes files are locked and unable to be written to, then the corruption would be that the Net Changes amounts would not synch to the Posted Transactions for the period(s) posted to.