12.04 - Stuck on reboot and shutdown

I've recently installed Ubuntu 12.04 and I love it. However I have one problem- I am unable to shutdown or reboot properly.

When I shutdown my laptop (Acer Aspire 5560) it hangs on the 5 dots and stays there.

When I reboot my laptop it does shutdown but when it boots back up it stay's on the Purple screen (no logo what so ever)

Thing's I've I'd to stop this:

• sudo service network-manager stop before shutdown - nothing





• Adding some lines the the GRUB file - nothing



• installed other Ubuntu versions - nothing


• sudo shutdown -h now - nothing

and some more.

At the moment I see a black screen in front of me with the text

 Asking all remaining processes to terminate [OK]

And the 5 dots with only the last one orange.

On other tries I got this thing:

modem-manager:could not get the system bus......

I first had Ubuntu dual boot Windows. And then it worked fine. However after a fresh install of Ubuntu alone I got this.