Increase the screen resolutions - Ubuntu (7.10)
To start, open a Terminal window by selecting Applications -> Accessories -> Terminal
Enter in sudo dpkg-reconfigure -phigh xserver-xorg and then your password.
Make sure that vesa is highlighted (it should be by default, but if you have to scroll up or down to get to it, use the up and/or down keys on your keyboard) and then hit enter.
Select the resolutions that you would like to be available for Ubuntu by using the arrow keys to scroll up and down, and the Space Bar to select them. Do not select resolutions that your Mac doesn’t natively support. Because I prefer not to work with Parallels in “Full Screen” mode, and my MacBook Pro is set to 1440×900, I’ve opted for 1228×800. When you’re done selecting resolutions, hit enter.
Restart X by clicking Control+Alt+Delete (backspace). Ta-da! Your new resolutions are now available.