AstralWanderer: Thanks for the info - a few other things to try:
Please confirm that you can run the Windows desktop at 1920x1080, and try running NWN with the desktop set to that size if you haven't already.
Check that you are using a recent version of Nvidia's Forceware drivers (though they have had performance problems with OpenGL software).
Change
compatibility settings for nwnmain.exe - Windows XP would seem a safe bet.
Ensure that you have Aspect Ratio scaling with the GPU doing the scaling selected in Nvidia's Control Panel (instructions
here) and that any monitor scaling is switched off.
Try creating a custom resolution in Nvidia Control Panel for 1920x1080 (instructions
here).
The reason why NWN is giving you problems while other games work seems likely to be its use of OpenGL (most other games use a version of DirectX). Running another OpenGL game and seeing if it gives similar problems (Doom 3 and Quake 4 being two other examples) may help pinpoint the cause of your problem.
My desktop is 1920x1080 and GeForce experience says I have the most recent drivers (this month).
Compatibility mode is set to XP SP3 and I changed scaling to GPU in the Nvidia control panel. Neither seem to help. Creating a custom resolution doesn't seem to change anything either. :/
I just downloaded Doom 3 (non-BFG edition) on Steam, changed it to 1080p, and restarted it and it seems to be working fine.
I really appreciate the help.