Comment 44 for bug 539163

Looks like I finally found the explanation...
My upstream bug was pretty quickly marked a duplicate of another bug and within that bug's comments I found this tip:
Go to Compiz settings (compizconfig-settings-manager), in there to general settings and deselect Lighting.

That fixed the issue for me. Apparently it's a bug in the display driver.

For now I am marking this bug invalid since it does not seem to be related to the kernel after all.