1. By HD PVR 2 are you talking about the Hauppauge?
2. The Hauppauge can accept unencrypted HDMI signals (like from a personal video camera), however, the signals from the Fibe STB would be encrypted and you wouldn't be able to record them. You would need to use component video (plus audio) - discussed in the various threads already linked in post 2.
3. The signals would not
come from the TV since TVs don't have an HDMI out. They would come from the Bell Fibe STB, but since you're probably using HDMI to go to the TV from the Fibe STB, you'd use component video to go to the Hauppauge from the STB.
4. If you're talking about a DVD recorder, which is SD quality, they also won't record encrypted signals via HDMI (if they even have an HDMI input) and would typically use a composite or S-Video signal (plus audio), which is usually not encrypted, but sometimes is.
As you can tell by the complexity of the answers and the links, this is not for the casual user. You really need to know what you're doing and you really need to want it. For the occasional user, this is simply not worthwhile.