Instead of using a Karmic repository and risking getting something you don't want (and really fowling up your system);

I used the repository at https://launchpad.net/~openismus-team/+archive/ppa for the Xephyr & XServer (is actually the broken component) replacement for Ubuntu Jaunty.

They have re-compiled the Xserver with just that single patch that was released to truck a while back to fix this issue.

Nathan.