I've had the same problem with my 2011 base mini with Intel HD3000 GPU a few times via HDMI to HDMI into my older Samsung 720p HDTV. I also had other problems such as black screens for 1 second a few times a day, and even kernel panics on restart. I fixed all those problems ever since I stopped using the HDMI out on the mini. I'm now connected via the Thunderbolt out into the VGA in on my TV via a cable I purchased from monoprice. I've been trouble free for a month now...