Unsure which since there are so many, but something's fishy.

Read your post. Maybe some EventIDs out of the Event Viewer could help the forum as well as revealing you perform scans with another web based virus check and have no spyware (Spybot?)

No mention if the OS is uptodate as well. In the past we could let a machine slide, but with all the problems, you install SP4 plus latest.

Bob