Review on StarTech.com Active Mini DisplayPort to VGA Converter for Mac/PC - 1080p Video - VESA Certified - mDP 1.2 to VGA Dongle by Gopal Baltimore

This saved our lives! Category 5 system. It kept losing signal and refusing to stay on for more than a second. After trying everything we could think of (computer replacement, VGA cable replacement, Cat5 cable replacement, projector replacement), we finally tried an adapter other than the standard Apple Mini DP-to-VGA adapter off. And it finally helped. I don't know what Apple does with their adapters by default, but they are not allowed to output a fully compatible signal. When we switched to this one all our problems were gone!