This morning I heard some music coming from my study. It turns out that VLC had started up playing one of my mpeg recordings by itself. I was defragging the hard drive at the time, so I wasn't sure if it somehow triggered one of the files to open.
Later, this evening, I went upstairs & noticed VLC sitting there on the desktop. I'm not sure what happened there.
Anyway, I've closed all the ports on my router for the time being. Nothing was turned up by SuperAntiSpyware or AVG, and I didn't see anything suspicious in the Event viewer. This is Windows XP SP2