I got it to install just fine with 7.1.2 and everything appears to work very nicely. Since I had saved games that I wanted to finish, I copied them into the newly installed directory for saved games. Crossover creates a hidden directory called .cxgames where it actually puts the installed files and once I found that, I put my saved games into there.
The only hitch came when I realized I had to upgrade the game. Normally, on an XP box, you just click the 'upgrade' button in the game menu. But this doesn't work in CrossOver. What you need to do is go to the bioware web site, then go to the NWN section and then download the full patch (it's like 310 MB). The under Crossover games, chose Run a Windows Command. Browse to the location where you saved the downloaded patch and click 'run'. This will patch NWN to 1.69.