can't sync songs downloaded from spiralfrog

I just got my sansa clip and I can’t seem to figure out why I can’t move songs from wmp to my clip. I downloaded some songs from spiralfrog and it tells me “not supported by device.” I already tried everything I could find from forums. I have all the new downloads I upgraded to wmp11 and I “formatted” my clip. I also put the clip in msc. someone please help.      

THanks in advance OlTroll