My STB changes channel to front row on it's own as well - It did it on Saturday during a recording of the BTCC
It also constantly fires up the interactive stuff on it's own which is a right PITA. The remote is in a cupboard as I have a TiVo. I know it's not the TiVo as I've covered up the display/remote receiver on the Pace and it still does it!
Channels are going blank as well more often these days. A reboot restores things to normal for a time, but it really is starting to annoy me.
Seriously considering upgrading to a Samsung in the hope of getting rid of these problems (as well as getting the 2 Meg BB I'm paying for) but don't want to be left with more problems
Cheers