I am running Ubuntu 11.04 on a G31-M7 TE mainboard Intel Duo core 2.7 processor 2Gb ram and every now and again it locks up with the screen being covered with a lot of coloured lines. The only way i can get going again is to reboot the computer . Switching the screen off/on does nothing for it. I have had a look at the system log but at the moment can't make too much out of that. It happens about once a day.
Some help in troubleshooting and fixing would be much appreciated.