I don't have an AT card, but the same thing applies to all cards. You don't have
the driver installed. Go to System| Administration| Hardware Drivers and let it
do the work. Scroll the list and install the correct one. Failing this search in
Synaptic for ATI and read the descriptions. Third choice is to install Envy and
build a driver.

Sys|Admin|HWDrivers just gives me an empty list. At the top of the box it just
says "No proprietary drivers are in use on this system".

None of the ATI drivers in Synaptic match my card.

...and Envy tells me that the only ATI driver it knows about is neither
compatible or recommended.

Seems I'm screwed. Lovely.

<sour grapes>
So much for Linux being good on older hardware.
</sour grapes>

This page may be of some help

http://intellinuxgraphics.org/documentation.html

For those of you that remember this thread...

Well, I've upgraded to 9.04 and, while the video card still shows as being
"unclaimed", Google earth works properly. So, it seems there's light at the end
of the tunnel.

For reference, it's a Sony laptop with an Intel video card.

from ubuntu forums workaround on intel video regressions

http://ubuntuforums.org/showthread.php?t=1130582