For two days we've had a flashing green lights on our three TIVO boxes (including the new one which was only recently fitted to replace the V+ box) - we've done the troubleshooting, no improvement. And for months now, BBC i-player, on-demand (and Netflix) keeps crashing the boxes making it impossible to watch them, so we tend to view those on either our smart TV or on the x-box instead (we have BT internet). When the engineer came out to replace our V+ box with another TIVO, he removed the forward path attenuator on the two TIVO boxes, saying that this might solve the problems with the older boxes crashing (though he went on to say that it can happen when demand is high - though I've continued to have problems watching off-peak). Since removing the attenuators, we've had problems with pixelation on screen on some channels and they still crash. The cost has increased and I'm beginning to wonder if I need to just quit Virgin media altogether, since we're not getting the level of service we had in previous years. I'm very disappointed because I loved having Virgin up until now.
Your description seems to indicate the signal levels are incorrect and need adjusting. He should have used a test meter to make sure each TiVo is receiving an optimum signal. Call VM and request a technician visit to check out the levels.