Add me to the list. I've been trying all day to get this scan to stop, but as with previous posters, I've been unsuccessful.
As far as I know, this just started last night. The only ray of light I might be able to shed is that I left the computer on over night, and when I went to use it this morning, the infinite scan was running. In my case though, there was a dialog box that said "FULL / Running" (I think my scan was titled "Full") and it had a stop and a pause button. But when I click stop, it restarts immediately.
Also unrelated - I found the Avast sidebar gadget annoying, so I went through the Control Panel process to uninstall it recently, but that was well before the infinite scan started.
Off to try the INI edit.