MediaPlayer no longer working on the emulator since r10?

I see this problem on mac os as well. In my case it happens when you enable "snapshot" for the emulator.
http://code.google.com/p/android/issues/detail?id=14953
You will have to delete the emulator and make a new one without "snapshot" enabled.

I had this problem on my MacBook Pro and found that I had to turn off my Bluetooth before launching the emulator.

Looks like the issue is only on my computer. I just tryed it on another computer and it work fine. I had some issues when I upgraded to r10 of ADT. Maybe there is something wrong in my development setup.