I'm running BUE v9.0 rev 4454 on an NT 4 Server. I backup to a disk on a Windows 2000 workstation. Users on the network copy their Outlook .pst files to their folder on there server where they are backed up each night. When the backup fails, the server is hung and has to be powered off/on to reset in the morning. The backup log is incomplete, and the last entry shows it is backing up a particular user's outlook folder on the server. There are 3 users folders it fails on, each having .pst's from 400mb to 700mb in them. If I exclude these 3 users Outlook backup folders from the job, the backup completes OK. I've deleted their file and when it's re-created by them it fails. Ran beutility on database, no errors found. Ran chkdsk on server volume, no errors found. No Dr. Watson logs, no errors in event log (entries in log stop about the time it hits the folder, then start again when the server is restarted). I would think if it were encountering corrupted data or if the backup disk is near full I'd get a message logged and the job would fail. I may try reducing the number of days backups retained, does anyone else know what could be going on?