I am having serious issues around the ABoS bunker. I am having repeatable lockups around Camp Forlorn Hope and Nelson specifically. It seems to get worse the further along your character is in certain quests and I can only get into Camp forlorn once and then thats it. Nelson seems completely unapproachable. I having been experimenting with workarounds as it blocked me from completing Still In the Dark because of one the locations to get the scouting report is in the freeze zone. I created a new character from scratch just for dead money and went there almost immediately after the build. I then finished said DLC and started out fresh in the wasteland to see what issues might crop up. One of the bugs has to do with Legionares over spawning in Camp forlorn as I once fast travelled there and saved immediately. If I was quick enough I could kill all the Legion and make Camp F playable but Nelson seemed hopeless on that save so I had to revert several hours back to just leaving the Sierra Madre.
I am now in the process of folling the quest in a more linear fashion the way the makers intended and Still in the Dark is past the point where there is a problem but I still found Nelson to be a major problem and have yet to try Camp F again. I am going to try a couple of things; one is to wait for a quest that requires me to go to Camp F in the future and two, clearing out Nelson from extreme distances in the hopes of bypassing the issues. For now I am trying to get as much done as possible before I attempt this again. One major problem I for-see is with Raul and his dialog triggers with Cpl Sterling so I am making sure to have Raul with me at Camp McCarran before I talk with him as he moves to Camp Forlorn Hope once you do the ranger/NCR quest "I Don't Hurt Anymore". I also wait till Cpl Sterling moves to Camp F before "acquiring" La Longue Carabine so if the lockups perist I am going to be so sad...
I have 3 other character builds that had none of these issues but I have yet to play Dead money with them. They are more complete but less desirable builds for me. I wanted a fresh one just to see what might crop up and to prepare for for future DLC's. I have all current patches and PS3 software is current also.