Re: CompizConfig messed up
I had the same issue when tinkering with CompizConfig and getting Sandy Bridge 2 acceleration working. Log out, at the log in menu switch to Unity 2D, start CompizConfig and it will complain of conflicts in this mode, just close the window, log out and change the mode back to Ubuntu. I believe it rebuilds a settings file, but I'm not sure which one, but it get me back to a working desktop.
I should have investigated more as I'm sure there's a more elegant way, but it got me back to a fully functional desktop environment. Planning to wait for a CompizConfig update before I try that again.
Acer Aspire X1930 running 11.10