I am using Ubuntu 12.04.1 and I have just installed the official Nvidia driver. now every time I log in, any gnome based desktop replacement (like unity or cinnamon) doesn't start correctly. It displays the ugly gray bars. Cinnamon looks like this:
Unity looks like this:

Is there a way to reset the gnome settings or what else can I do? I have tried to uninstall and reinstall cinnamon, but the problem is still present.