I recently ran updates in 12.04. I can't seem to tile windows side by side. Before I would grab the title bar of the window and move the window to the right. It then would be resized to half the screen size. I would then take the next window and do the same thing on the opposite side. Now, I can't seem to do that anymore. Anyone know why?
If you drag the window to the screen edge you should see an orangish shape where the window will snap to if you release. You can also use the
Cntl+Super+arrow key to snap the active window to one side or another.
Finally, this is a compiz plugin called Grid. Install and open compizconfig settings manager (ccsm) and choose Grid from the Window Management section. Make sure it's enabled and you can change settings there.