Windows Backup Utility hangs "Preparing to backup using shadow copy"

NTBackup hangs and I have to manually power down my 8400 XPS (Gen 3) at the point it is preparing to backup using shadow copy.  No error messages.  This even happens if I am just trying to back up the System State to diskette.  I'm wondering if my  RAID 1 harddrives are a problem for the Windows Backup Utility?  Could other applications be interferring?   

 

I have the same problem trying to back up all data to my Exabyte VXA-2 tape drive.  I'm running XP SP2.

 

I've used NTBackup extensivesly on my (unRAIDed) 8250 with no such problems. Both systems have pretty much the same software on them.