FO2 Mouse locking up, making game unplayable

[Takaosan]

I'm currently playing the steam version of FO2, currently in the Navarro base, which occured a different way to every guide says (no gas station entrance, just verti-bird squad there to greet me) but it seems that whenever i enter my inventory or a locker etc, my mouse becomes locked as if im in right-click command mode (whatever its called), this means i cant move or anything so it has rendered my game unplayable, i have restarted constantly and always same problem. Also on a side note, can anyone tell me why i cant seem to open the big vault door in vault 15? i cant get to V13 without getting in there