Yes, once. I had a backup of the flash and tried to use that to restore it, but it didn't work. Had to default and start from scratch. Defaulting and copying the parts back was a waste of time.

Was told by TS that "something got corrupted during the nightly maint" process. All in all, the 4E has been a pretty trouble-free VM, we've got quite a few out in the field. Just wish there was a reliable backup method (if anyone knows of one, please don't keep it a secret!).