Well, it hasn't started on its own in a few days now. Unfortunately, I wasn't completely scientific in trying to figure out when it happens (I changed multiple things at the same time). I stopped using GimmeSomeTune. I also use USB Overdrive 3.0.1. I specifically created an entry for iTunes and then unchecked the Enabled checkbox, effectively allowing me to use USB Overdrive for everything except iTunes. The one other thing I did was specifically click on the heading for Music in the Library section on the lefthand side of the main iTunes window. The songs it had been playing on its own in the past were in some of the playlists I created. I've had those playlists for quite some time, updated through multiple versions of iTunes. Perhaps I need to delete them and create new playlists directly in iTunes 9.0.1. So I guess the moral of the story for me is, if you have any sort of input managers, try disabling them and see if that helps. If the problem presents itself to me again, I'll come back and let you know.