OS X 10.9.3 Stock 6 core 16GB 256GB SSD. When I cold boot the nMP the second monitor will display random garbage while the main monitor is showing the grey screen. It hangs and I must shut it off and reboot again. After that the machine works flawlessly. Both monitors are 1080p connected by DVI<->mDP. If I switch thunderbolt ports, the other monitor becomes the main monitor and the second monitor again shows garbage and locks up on a cold boot a few days later. The nMP has worked perfectly until I installed 10.9.3. Windows works perfectly from BootCamp. I have: - Resinstalled OS X from the restore partition. - Run disk utility to repair the SSD. No errors. - Restored from a full Time Machine backup. - Run hardware diagnostics. Passed. - Ran the combo 10.9.3 installer on top of the existing 10.9.3 partition. Anybody seen or experienced this before?