Last weekend I noticed Avast!'s ball kept spinning and didn't stop. I checked the file shield and it keeps scanning 2 files over and over; I'm not sure if they're the same or not. Today I noticed it doing it again and it has got the scanned files to over 39K. Attached is an image to show you what I mean.
Edit: I just noticed since the file seemed to be in the recycle bin, I used CCleaner and now Avast! finally stopped scanning. Maybe you can find out why it is doing this.