Hi
Your correct it should work is there no way of testing it with the cable that came with the monitor just to check if its a faulty cable
Also what GPU do you have does it have dual DVI outputs and have you tried them both ?
Any dual link DVI-D cable should work assuming you are connecting it to a dual link output.
Not all DVI outputs on graphics cards or motherboards are dual link.
I've used this with the same monitor without any problems: OcUK Value DVI-D Dual Link M - M Monitor Cable (Black) - 3 Meter
You can also use DisplayPort if you have that output for your graphics.
I am sure my card is dual link cause the original cable works. One thing I just notice is that the cable I bought looks a bit different from the one OCUK sells. If you check the pic in OCUK link, http://www.overclockers.co.uk/showproduct.php?prodid=CB-067-OK&groupid=1929&catid=1754&subcat=, near the connectors there are Ferrite Cores. The ebay one does not have them. I guess that would be the reason?
ferrite choke is used to suppress high frequency noise in electronic circuits.
So that is not the reason the cable won't work. Hmm I guess that is just a crappy cable then. Is there any advantages with displayport over DVI? I might consider getting one.