Are you a developer? If so, report the bug. If not, IT'S BETA SOFTWARE, it will have some big bugs. The official release will not have the problem of killing the iPod app.
THIS IS NOT A BUG. There's already an erroneous thread on this. He just needs to resync with itunes.
Well then... that's a bug.
Yep, I am a developer. already submitted the bug and did a resync. the 2nd time I reinstalled 3.1 it corrected the problem... so the solution is 2 reinstalls apparently