Hi there,
This sounds like exactly the issue I've got - had for 12 months! I have a TiVo box about 3 years old (?). We have very reliable 100+Mb broadband but the TiVo box is cabled in directly by coax to the Virgin supply. This was done some 20 years ago. Every time we use "Catch up" - especially Netflix or I-Player, it will work for a while, anything from 5 minutes to 1 1/2 hours. Then the picture will freeze and after a few seconds a black screen with some generic message "We're having trouble playing this title at the moment, etc, with the tab "tvq-pb-101 (3.3.-302). As you say, as soon as the picture freezes, the second of the two permanent green indicator lights on the left of the TiVo box starts flashing. This always lasts for 3 minutes. When it stops, I can pick up the programme again. During this outage, I can tune to TV programmes in real time without a problem. Telephone support have looked at this three times over the months; each time saying they have made some firmware update or some similar tech fix and assure me that the problem won't re-occur. Then it always does.
I'll try phoning them again.