2009 octo mac pro, with 2 gt120s inside. I bought one of these: http://www.drbott.net/product/9601-MDOP/ and connected the macs MDP and optical audio to the device, and ran HDMI to my LCD display. No picture. Any idea what I could be doing wrong here ? I clicked "detect displays" in the prefs tab for displays, and I am currently running 3 other displays successfully... Has anyone used one of these adaptors with a 2009 mac pro before ?