I should mention that this is a V52 error and is becoming far too easy to replicate. UPDATE: I spoke with TiVo support and they seem to think that it's a weak OTA signal coming into the box. I'm skeptical because I know most channels come in with a strong signal (as verified by TiVo's own signal meter in Settings). They asked that I try a signal booster and report back. If it still persists, they'll swap out the box apparently.