Windows 7: Halo campaign

When i open up halo to play the campaign it gets stuck on the loading screen and i have to force close it....works fine on multiplayer though. i can manage to get a level to load by running it in safemode and then once it's loaded i can reload the game normally and play that level fine....but then when it comes time for the next level it gets stuck on the loading screen once more and the cycle repeats.

pics