Scooper,
I can understand that especially as yours is said to be 4GB. If you want to know if your memory size is genuine I suggest you load your player with music until the complete 4GB is full and then either,
a) start playing them all, if you can do that without having file corruption errors and player restarts or
b) select the last 10-12 music files you copied to your player and copy them back to your PC and see if they play or are corrupt.
If you can do this then please let us know as it would be good to verify that real 4GB players are available.
Thankyou