What you have is not dual-link. Dual-link is part of the DVI spec that allows a higher resolution on a single monitor. What you have is a proprietary connector that splits out into two different DVI connections, which themselves might be (but probably aren't dual-link DVI).

I'm sure that the end of your cable that plugs into the computer looks like a DVI plug but filled with the small pins and without the four larger pins and blade on one side. I've seen those before, too.