I got a new MBP last week. (2.5 Ghz Penryn, standard build, matte) I connected it at home to my 20" Cinema Display (which is about 4 years old). What I noticed the first time was that it blinked a few times (from the display screen to blue back to the display screen, back to blue, etc). And finally settled. It worked fine all weekend, and finally on sunday, it wont settle down anymore. When i connect the 20" cinemda display through the HDMI connector it just blinks over and over and over (blue to display back to blue). Anyone have any ideas of what could be wrong? and how to address it. I took the MBP back to the store and we tested it there with a cinema display and it worked fine. It blinks only once and then the new display is working. I also tested it at work with some DELL 20" monitors and it worked fine. So i dont think its the MBP hardware, but possibly something about the old cinema displays and the software on the MBP..