Comment 7 for bug 694480

We're going to be moving natty to its new X stack within the next week
or so. Currently this stack is available in xorg-edgers, and our
testing is showing it to be quite stable.

I'd like to have you attempt to reproduce your issue with this new
stack. If it still occurs with that stack, we can then take the the bug
upstream, or approach the kernel team or other appropriate groups about
it.

The PPA is available at:
https://launchpad.net/~xorg-edgers/+archive/ppa

Here's a simple way to install:
  sudo add-apt-repository ppa:xorg-edgers/ppa
  sudo apt-get update
  sudo apt-get upgrade

Then reboot your system to get to the new bits.

If you want to go back to stock Ubuntu, there is a corresponding
ppa-purge tool:
  sudo ppa-purge xorg-edgers
  sudo apt-get update
  sudo apt-get upgrade