You guys seem like experts, I can not figure out this problem for the life of me... I have a Mid 2012 Mac Pro with the ATI Radeon HD 5770 1024MB I recently purchased the LG 34UM95-P and have it connected via a Mini-DisplayPort to DisplayPort cable that is DP 1.2 compatible. Monitor works great, resolution is wonderful, however once the Mac goes to sleep, the monitor enters it's own standby mode, and then will not receive a signal from the Mac on wake. It will say "no signal detected" and go back into energy saving mode. For the first few weeks I had it, it would do the same initially, but after going back into energy saving mode, if I pressed the monitor power button, it would then receive the video signal and work normally. But now it will never get the signal. I have also tried going DVI-to-DisplayPort, same issue. This is not an issue when going from Mini DP to HDMI, however I only get 30Hz and this is unacceptable. It is impossible to find any examples online of someone with this same configuration and problem. I am fairly certain it has to with the Mac/video card, because my MBA and rMBP do not cause the same issue when using the same MiniDP to DP cable. Does anyone have any thoughts or advice on this? I've even begun looking at replacing the video card due to how annoying and nearly unusable this is. The monitor is about 6 weeks old at this point so I cannot return it. Anyway, any thoughts or advice that might get this working again is insanely appreciated. Thanks!