It's definitely possible; I vaguely remember taking an Xorg update around that time on the x server side, so I'd be surprised if they were unrelated.
I'm pretty confident that this problem is localized to emacs, though; emacs is the only application with which I experience the issue.
The issue does not occur with emacsclient using the XQuartz server on my OSX box, connected to the same daemon.
aptitude show xserver-xorg
Automatically installed: no
Uncompressed Size: 369 k
Depends: xserver-xorg-core (>= 2:1.11), xserver-xorg-video-all (>= 0~) | xorg-driver-video, xserver-xorg-input-all (>= 0~) | xorg-driver-input, xserver-xorg-input-evdev (>= 0~), libc6 (>= 2.7),
xkb-data (>= 1.4), x11-xkb-utils
Conflicts: xorg-renamed-package, xserver-xorg-renamed
Replaces: xorg-renamed-package, xserver-xorg-renamed
Provides: xserver, xserver-xorg-renamed
Provided by: xserver-xorg-lts-quantal
Description: X.Org X server
I will try today to find time to roll back to 24.2 and see if it occurs there. I'll try 24.1 as well, if time permits.