Similar Experience:
When using stock music app it will sometimes studder and then ends up "crashing" but really it just stops playing music - there is no force close message.
I used Winamp at the gym last night for 40 mins without any issue. I'm also unable to get PowerAMP to run at all ... so I think some others must be seeing some of these same issues.
You could try the following:
-Download and install Terminal from market
-Open it and type the following:
su
logcat > /sdcard/musicfaillog.txt
Switch back to your desktop and open one of the applications that is crashing right away and get it to crash. Once you've done that go back to terminal and ctrl + break or exit terminal
We'd hopefully be able to take a look at the log ... and maybe see something if the failure happens immediatley
You could also wipe the device:
1) Turn phone off.
2) Press and Hold; Back, Volume Down, and Power keys.
3) Continue holding all Three keys until device powers on and Recovery Menu appears.
Navigate using volume up/down keys, and Home key for enter.