Of course you can't man the gun if the crew aren't already doing so, just like you can't lock the UZO onto a target if the crew don't see it. it's a mistake, but there's not much we can do about it now.
I would say reinstall. I've never had that happen, but I can see where it's possible.
You might also try Jimbuna's All Weather Fix.
http://www.subsim.com/radioroom/down...do=file&id=391