wma files not authorized to play in wmp 11

I recently upgraded to wmp 11. Once I did this when I tried to play wma
files a window popped up that stated that "this computer is not authorized to
play this song. If you already own the song, sign in to listen to it." When
I click on the sign in I get MSN error 0x81460064. I have paid for these
files. It is only the .wma files that don't work. My MP3 downloads work
fine. I have been on the phone for hours to Microsoft Support and to date
they haven't been able to fix this problem. Has anyone else had this problem
and if so were you able to fix it and how?