I've been using Rockbox since I got my 5th gen ipod a few months ago, and never had a problem this reoccurring. Sometimes, it would freeze, but not as often as its been doing the past week.
I'd be playing my music, and want to switch to another song. I press next on the pad, the screen lights up half-way and freezes, or some garbage like 'unknown interaction etc etc' comes up. Its only been like this this past week. I tried to reinstall the firmware, and still got the same problem, and its only been like this since 3.3 (the official release, not the last updated).
I'm trying to see if its just a firmware issue or maybe a hardware issue, but i'm not sure where to put it...