I'll try clearing the game cache and see if that will work. If not, I will uninstall it and reinstall it.
I've put in nearly 90 hours with the first (and only) character I created, and have been playing Dead Money now for about 5/6 hours. I also have over 40 saves, which I do reuse by saving over (and not deleting them first).
I noticed a slight frame rate stutter in one building in DM last night, but it was only for about a minute.
As I've said on at least one other thread, I do find the issues that some people have with this game, on both the 360 and PS3, puzzling.
I can understand different bugs affecting PC users, but as every 360 and PS3 is essentially the same hardware apart from HDD capacity, I don't understand why everyone doesn't experience the same problems. And I'm not talking about quest/scripting issues, which may only show up in certain cases, but fundamental problems such as the DLC error, and not being able to start the game at all, or it crashing regularly.
I think this is something that Bethesda/Obsidian do need to look into.
It would be good if they could contact one of the forum members who's had major, recurrent problems, and check out their console to see what the issues really are (and perhaps give them a brand spanking new one in exchange!). Probably won't happen though ...