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

Saved our lives! VGA over Cat5 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 the problems we had were gone! Also, the adapter has deep screws (unlike the Mac) and snaps properly into the VGA connector.