Installing xserver-xorg-lts-precise will put you back on the 12.04 X stack for it to work (alternately installing xserver-xorg-lts-quantal will go back to 12.04.2), you'll want to purge the linux-lts-quantal packages as well.
Installing xserver- xorg-lts- precise will put you back on the 12.04 X stack for it to work (alternately installing xserver- xorg-lts- quantal will go back to 12.04.2), you'll want to purge the linux-lts-quantal packages as well.