Moved: This thread is more suitable in Linux-Games and has been moved accordingly to help your thread/question get the exposure it deserves.
Which resolution do you use in the game? It's probably different than your desktop one. NWN takes it (and all resolution settings) from X, so you need to change the way X displays it. First you need to identify the resolution. Try ctrl+alt+'+' and ctrl+alt+'-' combinations to switch between available modes. You should easily find the one the game uses. The desktop will be changes as the game is.
When you have it, run 'xvidtune' program (do it from console, will show later why). It allows you to tweak your resolution settings. Use the buttons and preview from time to time until you get the settings you accept. Now click 'Show'. In the console you'll get a line like:
"1280x1024" 167.25 1280 1344 1504 1728 1024 1025 1028 1072
You can now close xvidtune and come back to your normal resolution, but don't loose the line. You need to open X configuration file (/etc/X11/X.org probably in new distros). Find "Section "Monitor"" and paste the line you have before EndSection adding 'Modeline' before. The line should look like
Modeline "1280x1024" 167.25 1280 1344 1504 1728 1024 1025 1028 1072
Save it (you need to be root) and restart X. Then try to run NWN again, it should be OK now.
It may be patch level. Or on your side look int nwconfig.ini There's a variable that tuns item restrictions on and off. Don't remember how it's called, through.