Yes, all of the in-game resolution options are supported by my graphics card. I meant that I tried all resolutions (with the nvidia set to stretch the image to fill the screen, set to preserve the original resolution, and set to preserve the aspect ratio) with the exact same results: I reach the main menu and Scion's image (it is Darth Scion, right? It's been a long time since I last played) is corrupted. Typically, the menu is non-responsive (can't highlight or select buttons), and the game freezes shortly thereafter.
I tried rolling back my nvidia drivers on the XP partition to v 169.something (the first drivers to support the 8800 GT). Swconfig now recognizes the graphics card, but the corruption-freeze issue is still present.