Comment 8 for bug 76054

Many people are reporting this same issue - Ubuntu's xorg installer is not detecting monitor h sync and v refresh rates correctly, leading to a variety of problems such as failing to select a correct resolution and refresh rate.

The work around is to manually set the h/v values in your /etc/X11/xorg.conf file using values from your monitor's documentation. Feisty users can also try simply moving aside the xorg.conf file - Xorg itself is sometimes better at detecting your montor on the fly than the installer is.

A proper fix is going to take some additional research; meantime I'm grouping all these similar bugs as dupes.