My replacement MacMini arrived yesterday, it replaced the one Apple 'captured' to use their phrase.
I suffered the snow and video blackout on the previous MM which I was running extended desktop. I only saw the problem on the HDMI connected screen, the TB/MDP screen remained fine throughout.
So yesterday I first installed my Crucial 16GB upgrade, then I set it up and migrated my stuff over to it. Having set it all up I used it for a while as I updated the software, reauthorized some Adobe applications and so on. This was all without any incident.
I have been using it today so far without incident also, first this morning without any problems and again this afternoon, it was swithched off in between. It has been allowed to go to sleep on a number of occasions and has been fine afterwards.
Now the only difference is I connected the screens the other way around.
My current setup:
Eizo ColorEdge CG223W connected by TB/MDP - DVI 1680x1050
Formac 1900 connected by HDMI - DVI - 1280x1024
Previously the Eizo was via HDMI and Formac by MDP?
Both screens are in use, I have the application on the Eizo/MDP screen and floating windows to do with the application on the other screen. Currently I have Safari on the MDP screen and Console and Activity monitor on the HDMI screen.
I was asked by Apple once I had received the new MM to inform them if it was working OK, I will wait till Friday at least to see if I remain snow and flicker free.