I'm having the same issue, maybe I can bring a little light into the subject.
All I have on my Rockbox are mp3s, so I can't tell if it does this with other filetypes.
All the music on my Rockbox played fine in previous releases.
When I play a song, it plays about 1 second in, then I get the error "Data abort at 0002EA50", then it quickly changes to "Data abort at 4000139C". The Theme background stays intact, if that helps, but all other information disappears except the error itself.
I am using a 2Gig Ipod Nano (you know, the old two-toned ipod with a color screen), I'm using the lastest Rockbox release to date.
Any ideas?