DVI port one has gone out on two monitors so far.  DVI port one fails to get a signal from the computer while DVI port 2 does just fine and other tested monitors get a signal from the computer tower.  I know of two other individuals this has happened to and you can find there posts here:  forums.overclockers.co.uk

The port just stops responding and goes into sleep mode.  Just wanted you guys to know that this is a problem with three of us that I know of.  replacements have worked for a few weeks and the DVI port went out of the second one as well.  the 3rd monitor went bad with vertical banding and shutoffs.  That one was refurbished too.  Hopefully the 4th monitor will do fine.