Comment 7 for bug 878235

"I have downgraded xserver-xorg-core and xserver-common but the problem persists."

xserver-xorg-video-intel is the most likely package, of those that have been upgraded, to have caused this problem. Did you try downgrading that?

"I have also managed to downgrade libimobiledevice2 and libdvdread4 but all the kerberos stuff is blocked for downgrade by Bug 878263."

That is unlikely to pertain to the video problem that this bug is about.