Frame Rate drops on old classics

I recently obtained Fable: The Lost Chapters off a friend of mine with the old school 'box' and i noticed that in some sections the game seems to chug along. Notably when your in a town. Also, i noticed that the fan quitens quite a lot. Any ideas?

the framerate was horrible on fable. in fact if there were to many monsters or people on the screen at the same time the game would crash. so it was a problem in the original and was never fixed for The Lost Chapters or any other xbox form( BC, xbox originals).bigE27

Yeah, i was talking to someone else about it and they say it came with the game. Thanks for clearing it up anyways, least its not a fault with the 360. And its still great to play a game with a quieter fan