I remember from FO3 there used to be some issues that made it so you needed to use "archive invalidation" or something along those lines. I've googled this phrase along with FONV and found some similar workarounds. I've messed around with various settings in the Fallout_default.ini, Fallout.ini, and FalloutPrefs.ini..... and I also downloaded some archive invalidation fixes/mods from the FONV Nexus, but nothing seems to work.
I don't think this is a save game issue, because I've tried starting new games with no mods loaded... and then restarting the game with mods loaded and using the "clean" save created with no mods activated.
Perhaps someone could tell me the procedures(if any) they use to get mods working? It might also help if you could detail the settings you changed(if any) in the various .ini files.