I have downloaded and installed Ubuntu 12.04 Desktop (32 bits) in my HP Pavilion dv6 lapton. The installation live-cd works pretty well, and all the installation process is fine.
But when it finish and the laptop reboots, it hangs in a black screen with a blinking cursor.
No GRUB, no error message.
I know these are very little details, but I don't know how to be more verbose.