Wide load: Adding widescreen monitor support to Ubuntu
This one had me pulling my hair out for quite a while. (in fact at one point I had to reinstall becuase I messed up my xserver config file so bad that I couldn`t see anything from the log in screen onwards!)
After trying to manually edit the config files and failing a number if times I found out about this neat little wizard that walks you through and makes it slightly more difficult to mess things up.
run this command:
$ sudo dpkg-reconfigure xserver-xorg