I have a new LG 34UM95 that has been working flawlessly for a few weeks now. My wife was working on a usb device for our son and I came home to a white screen that wouldn't disappear until a hard reboot. Now, the rMBP won't see the monitor until I power down the monitor (pull plug) and start it back up. If I disconnect the TB cable from the rMBP to the monitor the computer tells me I incorrectly ejected a disc (the hard drive connected to the monitor) but it won't connect visually. I have reset the PRAM and the SMC and repaired the permissions. What else could be causing this. Computer is also taking a long time to restart. Much longer than it used to.