Comment # 13 on bug 1213787 from Takashi Iwai

(In reply to W from comment #11)
> I wonder why the problem doesn't occur when using XFCE window manager if
> it's a kernel/display driver issue at root.

It's a good question.  Might it be the way it's rendering, e.g. with composite
or not?

In anyway, it's confirmed that the problem is tied with the commit, and the
workaround is present.  Let's close for now.