I installed Ubuntu 13.04 today with gnome(First Ubuntu 13.04, then `apt-get install gnome-shell`). After this my boot screen is broken, you can see this here:

![broken screen](https://i.stack.imgur.com/U39zl.jpg)

This happened at Ubuntu 12.04 and Ubuntu 12.10 after installing `gnome-shell`(For gnome 3 desktop environment), too, at shutdown and start.
How can I fix this?

Additional information about graphic card and driver:

> 
> Name: GeForce GTX 560 Ti
> 
> 
> Driver: 310.44
> 
> 
>