One of the annoying things right out of the box is that the default screen resolution (1440×900) is not automatically detected. Instead, Ubuntu and Xwindows shows 1024×768 — which on this screen looks horrible on a widescreen LCD. Fortunately, this problem is easily fixed.
Open the terminal and run the following command:
sudo dpkg-reconfigure -phigh xerver-xorg
Go through the menus choosing the defaults and when given resolution options make sure to select the 1440×900 resolution. Once finished, restart X by hitting Ctrl+Alt+Backspace (save any unsaved work before doing this). Upon restarting the server the screen resolution should be set to 1440×900.
Now this solves the resolution issue in X but what about during startup or shutdown?