The game does often crash or freeze for me on loading screens, i remember those starting after one of the patches. Though if that happens twice in a row or more on the same door then there's a real problem.
Crashes when approaching an area isn't uncommon either, that goes away after waiting a couple of in-game days unless some mod causes the issue. A corrupted actor spawn can cause that, i remember hearing, so waiting for the game to respawn the actors in the area fixes that up automatically. If that area has worked before with the same mods, it's likely that issue. I've had those since Oblivion.
If it's not caused by those typical issues, it's likely mod conflicts messing with those cells. Run http://newvegas.nexusmods.com/mods/35999 and see if it warns of conflicting mods, and see if the mods you use require compatibility patches with any other mods. Also rebuild your patch.