Comment 23 for bug 40297

I'll see if my advice can be of any use.

From the bug report you referenced it seems that disabling splash from kernel boot options (in grub) has helped the reporters. You could try the same to see if your screen corruption is also caused by the splash, in which case it's probably useful to continue tracking the issue in that report. (Apparently - I don't know - they are still running a _framebuffer_ virtual console at this point.)

If disabling splash doesn't help, you can check if the corruption is instead caused by X by booting to text mode, and verifying that you are still running a framebuffer virtual console (instead of the "normal" or "extended" modes). If the corruption occurs when X is running, but is absent without X, your issue would seem related to this bug.

Hope this helps.