This happened after I reinstalled the fglrx graphic drivers. Is this a problem with Unity or Compiz?
It's a problem with Unity.
There's a bug tracker going on here https://bugs.launchpad.net/ubuntu/+source/fglrx-installer-updates/+bug/1069199
I got back by right clicking the desktop -> change wallpaper then clicking "All Settings" in the top left, then "Software sources" bottom center, Additional drivers, the far right tab, then reset it to the default open source drivers.