If anyone's having problems with LIVE or just wants to improve performance and how fast the game will load, renaming Fallout3.exe.cat to something else will cause the game to skip loading the LIVE dll.
edit: just finished the game and was completely meh'd by the ending i got.
"No, Mama. You can bet your sweet ass and half a titty whoever put that hit on you already got the cops in their back pocket." ~Black Dynamite