As the title says I can't shut down Ubuntu, when ever I press "shut down" the screen freezes and white lines start to show up (fading in) so does other black lines shows up in the screen, I waited a while and it just doesn't shut down.
I had that problem on installing Ubuntu, then I downloaded the Alt. CD (text installation) and had a smooth install (with 0 problems).
Edit: Yea, I can't even start up Ubuntu anymore..
Here is a pic: