There is a possibility that the 0xC0000005 error is caused by a hidden component of the SdBot worm, which was on your computer. I would’ve thought one of the anti-rootkit scanners would’ve remove that, but just to be sure, you can run the following removal tools to check:
http://www.microsoft.com/downloads/details.aspx?FamilyId=AD724AE0-E72D-4F54-9AB3-75B8EB148356&displaylang=en&displaylang=en
http://www.sophos.com/support/disinfection/sdbot.html
http://vil.nai.com/vil/averttools.aspx