KotOR 2 is an old game, using the same engine from an even older game. Disabling hybrid power might do the trick.
The best thing to do would be to uninstall the game, disable hybrid power following these instructions
. While you're in the BIOS, I would also look around in the menus to see if there's any way to disable the integrated 9100M GPU so that you're only running off the 9600M GT all of the time. Then I'd reinstall the game.
EDIT: Scratch that; there doesn't seem to be a way to disable it in your BIOS. You may have to set up a profile in your Nvidia control panel. Other than that, I have no idea what else to do.