NOKIA 6708...a peculiar problem

I just bought a Nokia 6708 & when I connect it to the PC and copy paste MP3 songs ONE AT TIME (from PC to Mobile memory card) everything is fine but if I copy paste several MP3 songs together I get a error msg after exactly 2 songs are copied...can anyone have an answer to this peculiar problem so I don't have to sit in front of the PC to copy one at a time?
Thanks in advance.