Rock Band and Rock Band 2 DLC Music Tracks Freezing

The original music tracks that come with the games work fine for both Rock Band and Rock Band 2, but every time I select a DLC track I can hear the song play at the music select screen but upon loading, the game just sits there.  It doesn't completely freeze as you can still see the musicians moving around in the loading screen but it never leaves the loading screen.  Has anyone gotten the DLC to work for them?  BLUS30050 and BLES00385.  Thanks!