To clarify, I am driving my display over Dual link DVI from my Nvidia GTX-660. The resolution limitation is specific to both the HD4000 + HDMI/DVI.

That ebay listing indicates that GTX 4xx's and 5xx's are supported. I would suspect yours will be fine.

Oh, I thought you meant that it was a limitation of the screen. That's a relief, then. I have currently had a 22" LG for a few years, it might be time to get a new screen!

Thank you for your help.

No, the HDMI spec is restricted in the resolutions that it supports, it's nothing to do with the HD4000, which could be a separate issue

HDMI 1.3 supports this resolution and there are numerous sources that indicate that the HD4000 will not drive a 2560x1440 resolution over a DVI port. Also, me and everyone else with a Dual link DVI port and HD4000 will tell you that it flatly doesn't work.