It most likely is vista. I had installed NWN on my new PC I had built with Vista (kicking myself for it now) instead of windows XP. Well, after I had installed it I was able to play NWN but I had to watch the intro movie ALL the time. If I tried to skip it NWN would crash.
Well, this got annoying and so I had stopped playing not being able to figure out what the was causing the problem. Then about a month later I decide to give NWN a try and as soon as the intro movie came up I hit a key and was able to skip all that stuff and my game works fine now.
I have come to the conclusion that one of the updates for Vista had fixed some sort of problem. I would imagine your problem has something to do with Vista.
I have the diamond edition and I'm assuming you have the separate expansion CD's or did.
Lastly, I know that the videos in NWN or story scenes would not appear for NWN users and only the narrators voice could be heard. I still have this problem and need to use RAD Video Tools to be able to watch them. This is due to the fact that patch 1.69 doesn't fix this problem for the Bink files contained with in game files. It is out dated and doesn't work with vista for some reason.
Anyway, as to why you're having this problem, who knows - it's vista and it is horrible. These are just the minor reasons why vista won't be found on corporate computers or servers anytime soon. It's not very friendly.
Sorry, for the long post. I just wanted to let you know that others are having problems with NWN due to vista and that it most likely isn't your PC if you've ran it before without any problems.
If you can't see the videos for NWN because of Vista you can google RAD Video Tools and make sure you download the Bink Video - The Video Codec for Games to watch the videos. You still won't be able to watch them in game but at least you'll be able to watch them.
If it work's for NWMAIN then at least you got that!
lol
