If that is
the graphics card that you have, then the problem is with the DVI-D port. The DVI-D port is only single link
sadly, while the DVI-I port is dual-link. Single link DVI is not capable of supporting 2560x1440 resolution; it has to be dual-link to get that resolution. So the issues you're having do tie in with that being your graphics card.
The solution would be to use a different input method. I think you can use the dual link DVI cable in the DVI-I port, but if you can't, I believe that monitor has HDMI and Displayport inputs, is that right? Displayport would definitely work to get you 2560x1440, and HDMI should
work as well, as long as the card's HDMI is at least version 1.4.
Hope that helps.