my pc with ubuntu server 12.04 was not able to shutdown correctly, so I followed this post http://rahulchand.blogspot.co.at/201...-shutdown.html and now it power off correctly.

But now Ubuntu is not booting: when I press the power button, the pc starts, and then I can see the Grub2 menu and after 2 seconds it loads ubuntu automaticly and than comes nothing, only a black screen.

But when I choose the first entry in the Grub2 menu manually it boots without problems.

Help me please, thx