Not sure where exactly to put this. I have a new rMBP as of yesterday but happened on my old laptop after Mavericks install, so not exactly a MBP issue I think. I have a 27 inch NEC wide Gamut Monitor PA 271w. I normally have the retina screen on the left and the NEC face on. On a normal boot before Mavericks I would get my Login screen on my Main Monitor the NEC than sign on and everything is fine. Here is what is happening now when I boot up I get a blank NEC screen and a blank retina screen ( which is normal for the laptop). Basically I can't see the login on the NEC unless I power it off or pull the TB cable and when I plug back in or turn NEC back on it boots the login screen back to the NEC and I can log on as normal. My settings are holding as far as display resolutions and arrangements so that is not the issue. Basically when powering on it is not booting the NEC. Now I have the Display on a separate TB port and my Raid0 box on another. Under system info I can see the Raid0 ( Pegasus Promise) box along with the TB ethernet cable. But I am not seeing my NEC in the TB info at all which I am finding kind of odd.