ubuntu 12.10 gnome (3) desktop defaults to classic mode

[odror]

OS: 12.10 (64bit).
video card: GTX 260

I have a very capable computer. Unity works fine.

When I try to use gnome it defaults to the classic mode with several additional (useless panels from the top and from below)

Does anyone knows how to fix that.

Thanks

[Zteam]

Did you install Nvidias proprioarty driver?

[odror]

Did you install Nvidias proprioarty driver?
yes