I have been looking around for this thing as well for my new 7900GT to support 1280x1024 in all games.I have so far been successful by getting the settings & manual resolution patches gained from this forum
http://www.widescreengamingforum.com/
Every detail for manually editing the setting in a game or for some games a manual patcher is provided.Every game that I have tried so far have worked except for Lost Planet DX9 demo which seems to be heavily screwed up on it's resolution front.No matter how much you try to edit it manually from the .ini file it won't accept that resolution.
