After Update gnome 3 fails

[Thorus]

Hi,

I allowed the updatemanager to do the update, he wished to do, and after an reboot, I can log on, but after that I get an message that my hardware is not supported by gnome, so it will do an fallback...

But after that nothing happens, I can see my mouse and move it, but nothing else...

I have an Notebook with an Clevo M860TU with an 9800M GT in it...

How can I get gnome back to work?:)

Thanks (sry for my english)