hi gacl, looks like nobody noticed your post
. I guess editing xorg is the best. Find the section with the resolutions, and be sure to add your desired resolution on the first place on each depth, or just in your default depth, if you are tired
Should be something like:
Modes "1280x768" "1024x768" "800x600" "640x480"
You will be using this always in the same computer?