The latest firmware that came out a few days ago, or tango? I have tango, and the issue is not resolved. I'd be very happy to hear if the issue is resolved by this small update that came out a few days ago (even though i don't have it yet).
As for the issue, I've been struggling with it myself. One thing I tried this weekend that seemed to give some good results is this: Start your song from the music player, hit the windows key to "minimize" the music player, and let your phone lock itself as opposed to using the power button to turn the screen off. I have my screen timeout set to 30 to seconds to make this easier. This seemed to work the two times I tried it, but we'll see.