[tadad1]

gazzataf, Because you are having problems adding files to your player my first responce would be to format it. At present you appear to be unable to do this. There could be any number of reasons for this, the partition table could be damaged, bad sectors on the chip or as mentioned this may be a hacked chip etc. A low-level format is a factory level format normally done to new storage media to prepare it for data storage. It checks the chip, sets cylinders and sectors then formats it. Basically returns it to it's original state. Because you can not format it the posted method using Testdisk will delete the partition completely then using the disk tool or Windows you can then create a new partition and then give it a low-level format. This should then allow you to access the player normally and store files etc. If your player is hacked (and it may not be) then you will end up with whatever the true size of your chip is and not the 2GB you thought.
Other causes could be a damaged or faulty chip or loose\poorly soldered pin connections. If this is the case then the whole process is not going to help at all and other than replacing the chip there is not much that can be done.