Reinstalling your video card drivers often fixes display problems.
If you don't have the correct ones installed, video drivers can be tricky to configure in Ubuntu Linux. If you have an ATI 3850 AGP video card installed in Ubuntu, the easiest way to fix your display problems is to reinstall the drivers. This takes only a short amount of time and can save loads of frustration from trying to manually tweak a configuration file.
Instructions
1. Go to "System" and "Administration" on Ubuntu's desktop and click on "Synaptic Package Manager." This is an application that gives you access to thousands of Ubuntu packages for downloading and installing.
2. Type "ATI 3850 AGP" into the search box. Hold down "Ctrl" and click on "xserver-xorg-video-ati-dbg" and "xserver-xorg-video-radeon-dbg." This highlights both entries. Right-click on either entry and select "Mark for Installation."
3. Click the "Apply" button in the middle of the top menu bar and select "OK" when it tells you the additional packages to be installed. Wait while the packages download and install. Reboot your system when the process is complete. This process will reinstall your video drivers.
Tags: display problems, video card, video drivers, your video