I'm having huge problems with my (rather highly modded, I admit) Fallout 3 game.
First, some characters (Colonel Autumn, Sergeant Benjamin Montgomery, Sally) constantly uses the "shhh" animation (they put their pointer fingers in front of their lips) in a loop and I believe it causes some stranges glitches. First, when I finish the main quest, my character stay stuck in the purifier chamber after the Ron Pearlman narration and therefore, I can't start Broken Steel (I'm not sure if Autumn having that animation glitch is related, but I believe so). Second, Montgomery doesn't appear when I'm supposed to join him (right after acquiring the Gauss Rifle) and he had that animation glitch when I first met him. Third, when I free Sally at Mothership Zeta, she gets in front of the airlock, but she's still stuck in that damn animation loop instead of crawling in.
I do have the unofficial patches installed (as well as Fallout Script Extender). The only major mods I can think of that I have installed are "A Note Easily Missed" and "Jessi Companion".
If you need more info like my computer specs (I doubt they factor in, but you never know) or my other mods, feel free to ask.
Thanks in advance.