I just tried to reinstall my Ubuntu 12.04 System so I put in my live-CD (64bit) and did a reboot. Then my computer detects it and it wants to boot from it.
Shortly you can see two lines of text and then it stucks on a blackscreen. In the top left corner you can see a "command-line" courser. A courser as it can be seen in the virtual terminal of Ubuntu (Ctrl+Alt+F1).