Not to be a troll or anything, but I've found tha the best way to manage music on my Ax- is not use it an a music player. If you're connected to power it might be alright, but during the day I'm not and listening to music on my x50v kills the battery in just about an hour and a half. A cheap sa-1 player ($50 for a 1 gig model) will last the whole week on 1 AAA battery.
Dotan Cohen
http://lyricslist.com/lyrics/lyrics/.../powerage.html
http://what-is-what.com/what_is/bug.html