I'm running Ubuntu 10.04 LTS (Lucid Lynx) on my Lenovo Thinkpad T60. I randomly get screen flickerings on my screen. Once it happens, it doesn't go away (unless I reboot my computer). I would describe the flickering as horizontal color lines appearing throughout the screen where the text is difficult to read everywhere.
I ran the following to see what video card is installed:
$ lspci | grep VGA
01:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility X1400
My question is: what's wrong and how do I fix it?