cannot move files on mp3 player

okay heres my problem...
when i sync music using WMP all the music that is sync-ed goes into a folder on my mp3 player, in that folder all the music is then organised by album name. usually i would just open two windows. one of the music in the folder. another to place the music from the music folder directly to the mp3 player.

but now for some reason, when i try to move the music it gives me an error window saying: "cannot copy 'song name': the directory or file cannot be created"

anybody know what how to either; make WMP stop sync-ing it into a music folder, or to stop the error window from appearing?

any help would be appreciated