Problem on background music subsystem

Ok, Jatris does not provide a background music but it can play an mp3 if you put it in a /jatris/bgm.mp3 file on the sdcard.
Tested on Android 2.3 it works flawlessly, but with Android 4.x the mount point of sdcard differs from device to device so Jatris may not find it.

Working on a more general way to identify the sdcard (both internal and external) and check for the presence on the bmg.mp3 file in a jatris directory.
This would solve the problem.