Comment 5 for bug 362704

Hi,
Had the same problem, solved mine by "remove" nvidia driver (system>administration>hardware drivers), restart ubuntu and set the resolution you require using the ubuntu program (system>preferences>display), restart ubuntu and reinstall the nvidia driver. One word of caution, if you are using compiz I would either change to the metacity desktop before removing driver or don't change any settings to compiz while the nvidia driver is removed.
hope this helps
Phil