Yea, I reinstalled and its still acting up. Another thing I have noticed is that it stops playing after the song is over once the screen has gone off, just for the first song.
My friend has been having same issues as you guys and she has the Samsung Moment, I'm running Pandora on my hero just fine...so it might be either Pandora or her device, and i'm betting its her phone since its been acting weird lately.
Generally Pandora seems to work ok for me, although I have experienced the issue you described a few times.
If that ever happens to me I make sure I'm completely out of the Pandora app (or reboot the phone) and then try it again.
The issue doesn't seem to come back after doing this (although I know this can be a pain to fix in the manner I described above).
Just figured I'd post because I have seen the issue occasionally.