I have a trouble with ATI driver with Ubuntu 12.04 LTS. When I install ATI driver in Ubuntu 12.04 via "Additional Driver", then I can't shutdown Ubuntu, it showed blank (black) screen and my laptop still run. Sometimes, my screen like that: http://www.youtube.com/watch?v=U9_iygesbBM
But when I install Ubuntu 10.04 and install ATI driver via "Additional Driver", it's very good and no trouble I've seen. It's sweet but 10.04 is old and is supported to 4/2013. So I want to know why Ubuntu 10.04 works good better than 12.04 with ATI driver (in my case)?