Motorola Droid X :: Music Stops Playing

When I am listening to the music app, or btunes, or mix zing; about one in four times I turn the screen off, the music stops playing. I've tried turning of my task killer, but to no avail. At first, I had a second issue as well: the music would play for only about 15 mins then stop, however, I managed to figure out that that was the 'Data-Off' timer I had set for the battery's 'Smart Mode' (though I'm not sure what data has to do with playing music stored locally). Nevertheless, swapping to 'Performance Mode' solved that. But for the life of me, I cannot figure out why a quarter of the time I turn the screen off, it kills the music.