Unknown artist/album

Every time I synch a song to my SanDisk player (m240 v 3.2.8A) it changes the artist name and album to Unknown.  This occurs whether I use Napster or WMP10.  I have tried to reformat the player, but that did not resolve the issue.  I have also tried WMP11, but again that did not change the situation.  I have been having this issue since I got a replacement device (first device got stuck on the startup screen and I had to return it).  I have called support on more than one occasion and have not gotten a resolution.  Support keeps telling me I have an incorrect version of software for my Napster.  I have a second m240 player with version 4.1.08A and it works fine!  I am at my wits end.  My OS is Windows XP Home Edition. 

did you tell support that you have a 2nd player that it works fine on?
Does it do it for EVERY song?