When you are using a HDMI connection and another to a different TV, you can get that error when you turn off the HDMI connected TV. One thing to try is to use a secondary HDMI of the TV if there is one.
Series 2 (PLS, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "652")
Roamio! Oh, wait, Its Juliet!
OTA! OTA! OTA!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!