I’ll just stick this out here in case it helps somebody who stumbles across it. I have Ubuntu on an aging Dell Inspiron. After a while, my display would start getting crappy. The interlaced lines in desktop icons and website images would fall out of alignment, making the image look smeared horizontally. I would also get a pattern of rectangles on my desktop, each made of black or white horizontal lines, so it looked like a sideways barcode label. After a longer while the system would bog down.
The solution was realizing that I had a Mobile Intel® GM45 Express Chipset. Using Ubuntu’s Unity desktop, you can find your graphics information by clicking the gear in the upper right corner and then “About this Computer”. With that knowledge, I searched Ubuntu Software Center for an appropriate driver. I just had to search “GM45”. From there I downloaded the “VAAPI driver for Intel G45 & HD Graphics family (transitional package)”. And that was it! Everything seems to be fine now.
Update Jan 3rd: The fix isn’t perfect, but my laptop still seems to be working much better. The problem has reappeared but the effect is much smaller and the system hasn’t slowed down. The reappearance has given me an opportunity to post a screenshot, which I didn’t think about taking before downloading the driver.
So not perfect, but still a big improvement.
Update (2013 March 14) Like I said, still not perfect. Others with this problem have found that having a mismatched memory sticks may be causing the problem; that is the GM45 chipset doesn’t work well if the two memory sticks aren’t the same. I have 3Gigs, so the problem may be solved completely if I upgrade to 4 or downgrade to 2. I’m probably not going to bother. More info on that here: and here: