Dell U2711 black screen when connected to Mac via DisplayPort

Question

I currently have a Dell U2711 27" monitor connected to my Mac Mini through DVI (it uses a DVI to mini-DVI adapter at the PC end). However, I cannot get the full resolution of the monitor 1920 x 1080 maximum is offered were the monitors maximum resolution is 2560 x 1440.
I did some Googling and seemed it required DisplayPort connection to achieve this. No dramas. I ordered a Mini-DisplayPort to DisplayPort cable.
I plugged this in and all I get on the Dell is a black screen. The monitor doesn't go into power save mode or anything like that, just displays nothing - an illuminated black screen.
I pulled out my MacBook and connected the cable to that, same deal. The Mac recognises that the cable has been connected (as the laptops LCD goes blue for a second or two while it detects the new monitor).
Any ideas?
I also had a DisplayPort to DisplayPort cable here which was included with the monitor from Dell, which I will test aswell when my miniDisplayPort to DisplayPort adapter arrived.

Answer 1

Yes, that is one means, but...
However, HDMI 1.3 can also carry resolutions higher than 1920 x 1080 - check out http://en.wikipedia.org/wiki/HDMI - not really an option on the Dell monitor though, as it only supports up to 1080p on the HDMI connection. However, there is a thread elsewhere on the internet of a user who forced his Windows laptop to use 2560 x 1440 resolution via the HDMI output and the Dell monitor accepted it!
In addition, so can DisplayPort - as per my original post.
The Apple Dual-Link DVI adapter is plagued with issues and has a lot of faults, so I'd rather avoid it. It is also significantly higher priced than the above option of DP.