The cable with the extra pins probably is using a dual-link DVI connector instead of a single-link connector. HDMI's video section is essentially single-link DVI; we've recently discovered in an interesting 990 thread that dual-link DVI connectors can in at least some cases allow HDMI audio to pass through the DVI switching on Outlaw's gear. What may be happening is the dual-link DVI connector could be using different pins to carry the video than the single-link DVI connector on the other cable, causing the video signal to not get through. It shouldn't happen, but it's still very possible. A second single-link DVI/HDMI cable would be a good test of this, and Blue Jeans Cables identifies their DVI/HDMI cables as single link.