there is a Reg Edit that will allow the screen to turn standby and still let the music play for the Windows Media Player.
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Contro l\Power\State\Unattended]"WAV1:"=dword:00000000
Also view this thread for a reg file that you can import if you dont want to do the change manually
http://forum.ppcgeeks.com/showthread...ing+Unattended