I recently replaced my Dell Ultrasharp 2408WFP with a pair of Dell Ultrasharp U2311H displays that a few people were raving about on here. I've had them for two weeks now and I've been noticing a regular, vertical stripe pattern all the way across both of them, especially noticeable in mid-greys and desaturated hues. One is connected to my Mac Pro 4,1 via DVI, the other via a Monoprice Mini-Displayport to DVI cable. I've tried Factory Reset and LCD Conditioning with no success in getting rid of them. Has anyone else encountered this? Did I get a pair of duds?