yacc, The seller is bullshitting you, there are no 4GB chiPods, the largest at the present is 2GB. Your fake 4GB memory chip was hacked so that Windows wouls read it as 4GB but it is really only 2GB. When you formatted the player you removed the hack and now your player is eporting it's true size. This is why you were having the problem in the first place because Windows was trying to copy files to memory that does not really exist.
If you want to conferm your chip size you will need to open your player and check the memory chip serial number against this list of Samsung and Hynix chips.
http://www.mympxplayer.org/samsung-a...rs-vt1692.html
If you look through the forums you will find many posts on the same problem.