Dual link only applies to DVI-to-DVI cables. I can't tell for sure from the picture at Blue Jeans, but I think the DVI connector on their HDMI-to-DVI cable may be single link (which would kill my initial theory). If you can, look at the DVI connectors on your two cables and see if they have a solid group of 24 pins on the left side (dual link) or if the middle third of that group is missing (single link).