Ubuntu 12.04 does not Shut Down at all and gets Stuck on 3 or 4 dots
To shut down and power off from the command-line with shutdown, the correct command is actually:
sudo shutdown -P now
However, if that doesn't work, press Escape when you first see the splash screen with the dots. That should show the messages "behind" the splash screen. Then update your question (by editing it) with the full and exact text of the messages you see.
The correct command is sudo shutdown -h now. Try this. Hope it will help.