FYI - I have installed the original ATV software from the smallATV.rar file that is on torrent sites, updated to the latest standard firmware, made the change to the HDMI output to RGB High, then installed Openelec Daily Build 9791 and after a good start, I now have the Pink Screen issue again.
When I first installed Openelec it looked fine, but since I have been trying to sort out a problem with the framerate output, and have been changing resolutions and framerates, after a reboot the pink screen has appeared, and now wont go away.....
So, what do I do now!?