Picture break up for about an hour earlier, OK now.

Earlier this evening we started to watch a programme that had started recording about 15 mins previously. The picture was totally broken up.

We switched to live TV and that was also broken up. I restarted the Tivo 6 box, but it made no difference.

We then watched a streaming programme for about an hour and it was fine.

Then tried to play the original programme that had recorded an hour previously and it was still broken up.

Then I recorded something new and it played back fine and live TV was (and is) also fine. Old recordings also seem to be OK.

So it looks like there was a temporary signal problem for about an hour, which has now cleared itself.

I just ran the on line diagnostics and it said there was a problem connecting to the TV and wanted me to restart router etc. This made no sense to me as streaming was fine and Settings > Network status said it was connected with excellent signal.

Is it more likely that the picture breakup was a temporary problem at Virgin's end or with our box? 

Thanks