I've had to use warranty on my similar, but non-ultrasharp (TN, not IPS) monitor. Let me tell you, there's a reason they coined the term "Dell Hell". I logged everything I did when talking to them. All in all, I spoke with over 20 different people at Dell and spent (adding all the time) over 24 hours on the phone with them. Three monitors later (one broken, another two the wrong model) I managed to fix my problem, but what a pain it was...
I agree dell sucks when it comes to warranty