I am totally stumped with this one. I have a W2K server running Veritas Backup 9 for Windows Servers. About 2 out of 5 times, the backup fails and both the backup error log and W2K event viewer show "The storage control block address is invalid" as the reason for backup failure. I've reinstalled the backup software, updated tape drivers, installed all updates and patches, changed tapes, and still can't stop this message. It appears at seemingly random which makes it even more difficult to troubleshoot. No applications are having any problems and everything works fine in all other respects (as far as I can tell). I can't find any info anywhere on what this error even means! Veritas won't help me without a hefty fee, but their free email support never answered my question. Any ideas??