After I first upgraded to Natty from 10.10 I went to fix my Compiz settings. First, the rotating cube wouldn't work. That was disappointing but not a huge deal. Later, every time I changed a setting in Compiz, my whole top toolbar with my clock, keyboard settings, calendar, etc. disappeared. I brought it back with a reboot, but that was only temporary.
Then I tried to install my nvidia drivers (I'm using an Asus UL50V) and after they were installed, I rebooted. Upon going back into Natty I was informed that Unity had crashed and was not compatible with my machine (I had already been using Unity for about a day at that point). Now I'm just running in Classic mode.
How can I get Unity back up and running? And once I do, what is there to do about my problems in the first paragraph?