Whew, I made it through chapter 2. I've never actually done that before so I was stoked.

Anyway, I was in the Host Tower and started having some 'issues'. One the first level, I was at the teleporter, and I got stuck to the wall. I finally managed to get away. I tried several things, including completely exiting out of NWN and restarting. Anyway, what finally worked was getting into debug mode then putting my pointer at a location, then clicking left mouse, holding, and clicking the keypad plus symbol. OMG.

The other weirdness was on the level where the helmed horror is created. Instead of following, I led the way (ha) and hit the door. My henchman joined me. When the helmed horror arrived, it started attacking my henchman! I told my henchman to leave. But after the helmed horror assisted with all the monsters inside, it went after and finished off my henchman! Well, fortunately I had saved the game before going to this level, so I just reloaded. This time, before the helmed horror was created, I told my henchman to stay put. I followed the helmed horror to the door as it seemed to just know what it was supposed to do. My henchman stayed in the other room the entire time and was still alive after the helmed horror disappeared.

I also had trouble when I first started using the teleporter. I would stand on the portal and nothing would happen. I finally read somewhere to move with tiny steps and it would work .... so I had to do that for the first few levels. Eventually just stepping on the portal worked.

I am using Windows Vista. So is any of this behavior usual? Is it specific to Vista or does that matter? But, at least I was able to get through them all and on to Chapter 3. :)

Though you seem to be experiencing just about every NWN glitch there is, yes, I've either seen or read about all of them. So, just bad luck. There are a lot of things in NWN that they simply can't seem to consistently fix, so it's not uncommon to experience the same bugs that were supposed to have been fixed in one of the official patches.

I run NWN in Vista, and have all these glitches pop up erratically. It got a bit better when I set it to run in XP compatibility mode, although independently written modules I play tend to have more problems than the OC.
I also have video rendering glitches that give people solid colored heads at times, usually red or turquoise. It's kind of funny, really.