Correction: the package is available for Quantal. However, I had xserver-xorg-core 2:1.13.0-0ubuntu6 installed, and ...ubuntu6.1 was not installed automatically as an update. Once I manually ran "apt-get install xserver-xorg-core", it installed the update and X worked.
Correction: the package is available for Quantal. However, I had xserver-xorg-core 2:1.13.0-0ubuntu6 installed, and ...ubuntu6.1 was not installed automatically as an update. Once I manually ran "apt-get install xserver-xorg-core", it installed the update and X worked.