Gnome fallback I can't click on login icon, only highlight it

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http://askubuntu.com – I have 12.04, and I would do virtually anything to be rid of Unity. I downloaded Gnome fallback and Gnome shell (do I need to have only one installed?) but when I go to the login screen i can only highlight the ubuntu icon, it won't click or open any menu so I can't use Gnome Classic. (HowTos)