For the last few months I have been struggling to find out why Fallout 3 has been freezing with some mods that should not cause the game to crash(like making eyes glow or making some normal characters companions) and figured I'd post what I have found out:
Bad mods that just cause the game to freeze, ie when entering your house or when you try to save, just don't work with the 360 version and just CAN'T be used.
If any mods are enabled and you get freezes randomly it is probably not any mod in particular the game is just freezing because mods are enabled.
Going into the DC city, or Rivet City may cause the game to freeze because too many things are being loaded at once, the same applies sometimes out in the wast land near the city as well if you are on a hill and the game starts to get choppy then you will most likely freeze. Making enemies Gib(blow apart) can also be the cause of freezing. To get out of these freezes I always have to open up the dvd drive which sends me back to the dash.
I have yet to have a freeze happen while indoors, or even in Megaton which makes me believe this is a outside world problem.
I also posted a video on youtube about what its like when I freeze, if this happens to you too please post here to see if these are also the symptoms you get or are exactly what its like, and/or any anomalies you might have experienced. Please post if you have patched fallout 3 and what Title Update you used and if you used archiveinvalidated or not.