Apple's own Mini DisplayPort to Dual-Link DVI Adaptor - the one you use to connect a Mini DisplayPort to a 30-inch display - has problems. These problems were never fixed with a software update, unfortunately. But Kanex thinks they can do better.
Kanex, if you recall, does MDP to HDMI adaptors, so they're already familiar with the technology. They also tell me that their adaptor is smaller than Apple's first-party ones and does not have the display problem. It retails for the same - $US100. [Kanex]