For me it seems to be a problem with Compiz because the "Ubuntu Unity Plugin" isn't activated. I think it was the upgrade from your classic session into "Oneiric" so compiz didn't activated the Unity.
But when you prefer the classic session, open up one of your desktop-folders i can see on your screenshot. Here you can navigate to
Here you can find Ubuntu Software Center and the Terminal (and perhaps still Synaptic Package Manager). So, when you have this, open one of your preferred programms. Way 01, the Ubuntu Software Center: Just search for "gnome-session-fallback". Way 02, the Synaptics Package Manager: The same way as in Software-Center,
Way 03, the Terminal:
sudo apt-get install gnome-session-fallback
When you had installed the gnome fallback session try to logout. You'll find a "gnome-classic" session and the same without any effects.
By the way, in the applications folder (mentioned above) you can find "Compiz Config Settings Manager" Here you can activate the Ubuntu Unity Plugin and your unity experience will start.
I hope, I was able to help you correctly