Have you tried formatting your player with the "
MP3 Player Disk Tool" from the
AMV Convert Tool 3.68 (MP3 Player Utilities 3.68)?
What you can also do is format the player from Windows using the "Disk Management" tool within Windows.
Quoted from s1mp3.org:
"This is a known problem, and on most of the players, it's caused by a player formatted to handle more memory than the memory chip allows."
You can also look at this post for further help:
here.
Hope this helps.