On every Gingerbread build I have had the problem of my Droid X rebooting after 2 or 3 songs on Pandora when I am connected via bluetooth to my Altec Lansing SoundBlade speakers. I thought the official update would of fixed this but it hasn't.
I use a bluetooth connection to stream Slacker Radio to my JVC car stereo and I don't get a reboot with that. Sometimes Slacker just kind of "disappears" and sometimes it comes back, sometimes not. But thankfully no full reboots.