I have had my new Mac Pro for a few weeks now...(and I love it), but I cannot shut down the computer with the screen command from the menu bar. It starts to shut down and close things but never completes the shut down. I have to bold in the power button to do a hard shut down in order to turn it off. I don't know if this has something to do with the HDMI connection to my SONY television...but...that certainly is my first suspicion. Anyone have this same problem?