Unable to run backup

[JeffT]

When attempting to run a backup on Plesk 8.1.1 server, I am receiving the following errors in the event log and obviously, I am not able to run a backup.
Any help would be appreciated.


Event Type: Error
Event Source: Plesk Miscellaneous Service
Event Category: None
Event ID: 1
Date: 8/12/2009
Time: 8:54:58 PM
User: NT AUTHORITY\SYSTEM
Computer: SERVER
Description:
Unable to on user (thed) scheduler: (-2147024882) Not enough storage is available to complete this operation.









at RaiseException in C:\WINDOWS\system32\kernel32.dll
at CxxThrowException in C:\WINDOWS\system32\MSVCR71.dll
at 407020 in C:\Program Files\SWsoft\Plesk\admin\bin\plesksrv.exe
at 45002A in C:\Program Files\SWsoft\Plesk\admin\bin\plesksrv.exe
at 450574 in C:\Program Files\SWsoft\Plesk\admin\bin\plesksrv.exe
at 45B42B in C:\Program Files\SWsoft\Plesk\admin\bin\plesksrv.exe
at GetModuleFileNameA in C:\WINDOWS\system32\kernel32.dll
Execute file name:


Event Type: Error
Event Source: domainmng.exe
Event Category: None
Event ID: 1
Date: 8/12/2009
Time: 8:54:58 PM
User: N/A
Computer: SERVER
Description:
Execute usermng access on failed: Unable to on user (test) scheduler: (-2147024882) Not enough storage is available to complete this operation.
at (domainmng::sysusers_on_off line 412)
at Turn on domain test.com (state=0)(domainmng::turnDomain line 141)
Execute file name: C:\Program Files\SWsoft\Plesk\admin\bin\domainmng.exe