I want to install the ATI driver to be able to adjust the gamma of the monitor.

I entered System Settings -> Software Sources -> Additional Drivers and installed a driver from AMD's 5400 series.

That made the panels and window borders disappearing. I could see the wallpaper, use keyboard shortcuts and open the terminal and access the menu from the work area with the right mouse button, but no longer able to access the launcher and applications directly.

Ok, with a bit of effort went into the same panel installation and managed to install the driver X.org X Server, which was the old, and everything returned to normal.

But now the gamma of the monitor remains bad.

It should work, because in Kubuntu, which had installed before it worked correctly, and the Ubuntu virtual machine too.

ps.: Ubuntu 12.10