manu1991, did you format it as fat or fat32? The formatting must be done in fat I think or else it will cause errors. To be much safer, I always use the format tool that came with my player (in the mp3 utilities cd). It has a few formatting options (quick format, full format, low format). Try all of them one by one and see if that fixes your problem.
For now, don't try messing with the firmware..as you can cause yourself a lot of trouble.
Hope this helps
