I gave up on trying mp10. I've been using GSplayer for my mp3s which is way cool and real easy to use with lots of functions. You may want to check it out here:
http://www.pocketpcfreewares.com/en/index.php?soft=701
I also have tcpmp for playing video files or streaming from internet.
You are right about Microsoft and Dell though, I'm very dissappointed with them also!
cheers!