I have my old premier setup for just OTA these days, and when I turned it on to a station that has just about the strongest signal I get, a blue box was floating over the screen saying something like "Problem with signal on this channel, retrying".
However, the picture behind the blue box was faultless, not the slightest glitch. The sound was also perfect. It just felt like keeping the blue message box on the screen for some reason.
Rebooted and the message finally disappeared. Now I just get a perfect picture. Never had that one happen before. I wonder if it is unique to OTA?