Windows media player albums inaccurate

after reinstalling WMP11 and then adding music to the library lots of the album covers(pictures) are repeated on albums that they don't belong to. when i right click on the album and select 'update album info' nothing happens. if i click 'find album info' and choose an album cover, it doesn't change the cover... i've restarted pc and covers are still incorrect... how do i fix this? i have lots of albums, fixing one at a time will take forever. is there a way to clear and reenter all this info again?

dim 2400

winXP

SP3