i am still having problems with this in Snow Leopard.
All 3 apple products, top-of-the-line Macbook Pro, 30" Apple Cinema display, and dual-link adapter. I have this horrible feeling Apple is just going release an update to the 30" displays and just *forget* about this issue..
https://forums.macrumors.com/threads/776842/
As long as your Eizo Monitor has a display port you'll be OK with just a DP to MDP cable.
You should get that exchanged and try the newer firmware. I am stuck with the last non-Unibody because of the issues. Don't feel like trying my luck. But as you already got the hardware might as well try it.