I am having a similar problem with horizontal black lines as described in http://en.community.dell.com/support-forums/peripherals/f/3529/t/19502072.aspx . In addition, at strange times the video goes black for 2-3 seconds and then comes back. Has any progress been made on the black line issue? I'd hate to exchange this new monitor and receive a "used/refurbished" U3014 with the same, or worse issues.
About the video going black for a few seconds and then coming back; I ran into this with my U3014 as well. I had it connected to my 2nd PC (as a 2nd monitor for that PC (would switch input and then tell that 2nd PC to enable the 2nd monitor)).
Once I disconnected it from this 2nd PC and only had it connected via a single cable to my main PC it worked fine.