Rebooting used to be TiVo SOP
If the latest TiVo boxes are anything like the original Series 1 TiVos (mine still going strong after 15 years) it's standard procedure to reboot in the event of an upstream failure - in the case of the S1 it will reboot if it's not receiving a TV signal (the assumption being the encoder, decoder or some other part of the chain has crashed/locked up). It's an extreme, but pragmatic, solution for a problem that happens very rarely.
If some part of the Virgin network or cable system is down this could easily explain the behaviour of the box which will keep rebooting until normal service is restored.
Biting the hand that feeds IT
