Sorry
Did you delete the file? Deleting dll's, is never a good thing. I'd reccommend, uninstalling, then reinstalling Spybot. However, after unistalling spybot, update your avast antivirus, (both the iAVS and program) then reboot your PC. Then install Spybot. Avast released a patch to the antivirus definitions, that was targeting spybot and other program files and generating false positives.