I installed Ubuntu 12.04.4 LTS along side Windows XP, Dell Inspiron 531. I then rebooted my computer. The message "cannot display this video mode optimum resolution 1440 x 900 60HZ" appears. I hit enter then I get the password screen but I am unable to operate the mouse to be able to move the arrow into the box to type my password. Then after a few seconds the screen shows a mauve color then freezes. My monitor is a Dell SE178WFP Flat Panel Monitor. I would appreciate any help you could provide.