Comment 6 for bug 1085338

I'm not able to reproduce on a 1920x1200 Dell monitor running -ati on precise on a PC, although not with an HD 6310 (I don't have that card).

If you can suggest other information that would help us reproduce the bug, I'm willing to try. But since you've ruled out it being a recent regression, and ruled out that it's the laptop, then next guess would be it's some irregularity in the Sony laptop itself or the video card. Did you test against xorg-edgers and mainline kernels? Doublecheck for bios options relating to display? You might try contacting the manufacturer, although I don't know whether Sony supports Linux at all (afaik they don't have an OEM contract with Ubuntu; if they did we could try working with them on our end). If that's not feasible, then I'd suggest forwarding the issue upstream to X.org; perhaps the problem will be more evident to them.