Since doing a fresh install of 12.04 on a Revo3600 I cannot get the "Additional Drivers" app to work. When I try and open it I get a message "Searching for additional drivers...", then the message disappears and nothing happens.

Any ideas how to fix this? I basically want to check that my nvidia drivers have installed correctly so I can use VDPAU. The "NVIDIA X Server Settings" app is installed. Does that mean it's working?