Please check "memory info" in "system utilities" menu of player.
You are not the 1st to have this problem.
I suggest that you return it to the seller for a refund. 4gb chips are not available yet. Max is 2 gb, unless it's a HDD player.
You may learn something here:
http://forum.s1mp3.org/viewtopic.php...ht=lost+memory
Good luck !
I.