Remember that the MS Blast and other varients of such are not stopped by your antivirus.
http://groups.google.com/groups?&q=Background+Task+Server+%22Encountered+A+Problem+and+Needs+to+Close%22 seems to lean towards a WORM issue.
Try this one -> http://www.microsoft.com/security/incident/blast.asp
Every time I reboot the computer I end up with the "Background Task Server Encountered A Problem and Needs to Close" error message within a minute or so.
Anybody know what causes this or what can be done about it? I'm using fully updated XP on a Sony GRV550.