Comment 10 for bug 868684

As far as I can tell this problem seems to be fixed with the new intel driver.

xserver-xorg-video-intel:
  Installiert: 2:2.19.0-0ubuntu1~xup1
  Kandidat: 2:2.19.0-0ubuntu1~xup1
  Versionstabelle:
 *** 2:2.19.0-0ubuntu1~xup1 0
        500 http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status
     2:2.17.0-1ubuntu4 0
        500 http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages

With the default packages in ubuntu precise I still had failing vblank counters in my Xorg.0.log

If you take a look at the release notes[1] you can see the following line.
- Prevent waiting on scanlines whilst not in control of the VT and therefore whilst referencing foreign CRTC configurations.

To my mind this may have solved the problem.
I hope this information is helpful for the others that have this issue.

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[1] http://cgit.freedesktop.org/xorg/driver/xf86-video-intel/plain/NEWS?id=444da84c47266bcbbdf5121507901de8eb36f11b