I only recently started using Ubuntu a few days ago (11.10), so sorry if I fail to mention specific things that may help someone answer me. That's probably why this is going to come out wordy.
I have a Dell Inspiron 1501 laptop, and I've been looking around to see if there was a way for me to install the graphics driver (ATI IGP Xpress 1150) so I could use Unity 3D. I wasn't sure if I was actually already running it, but I wanted to see if I could enable my graphics driver anyway. As far as I knew, doing that would make things run smoother. I followed the instructions someone placed here: Jockey not detecting my ATI IGP Xpress 1150 and it installed...something.
Things were still working fine after I did that, so I went into Compiz to see what kind of things I could tweek. I don't recall what the last thing I tried to enable was (it might have been Desktop Cube) but right after that, all the windows I had open lost their bars (forget the word for it, but you know the bar that has the minimize, restore and close buttons on it), the launcher disappeared, even the taskbar. So I restarted my laptop, and now the workspace switcher, instead of a square that showed each workspace and allowed me to move up and down as well as left and right, is replaced with a straight rectangle that only allows me to move left and right (still with four workspaces). I had only seen that before when I ran Unity 2D as a test, but I know I'm not using 2D, and I'd like to go back.
For what it's worth, I don't think it really had anything to do with me attempting to install the driver. As things are now, things are moving less laggy on my screen. But I really liked the way the workspace switcher had worked up until now. I think it was something in Compiz that I accidentally disabled for something else, but I'm not sure where to begin to rectify that.