I am using Ubuntu 11.10 in Sony VAIO.
The workspace manager worked in the beginning. But now, when clicking on the workspace button, the 2x2 grid is displayed. Only the upper left workspace is highlighted and the other workspaces are black and faded.
Only the upper left is selectable, which means I effectively have only one usable workspace. I tried CCSM but changing the grid size there had no effect at all.