How bizarre! The minute I join, login and post my problem, the scan stops! Coincidence or part of a strange plot to get me registered? Or perhaps some kind of strange halloweeny type shenanigans! Hmmm!
No, just a little demonstration of the power of the community forums :-)
From what you say it's scanning when it's not scheduled to scan. Well, that's a bit puzzling but not a threat to your PC or anything, so I shouldn't worry too much.
If it happens again come back and ask someone why it's doing it, but better place your question in one of the other sections for a faster response. I would think the best place for it would be in
McAfee Communities > Home and Home Office > Virus and Spyware Protection > VirusScan 14 - 2010
For now, if the problem's gone away, perhaps you should mark this as 'Answered' (look up towards the top) or delete the thread as not relevant (look in the Actions section).
Happy Halloween ...