Firewire Issue Resolved, I Hope
The previous post gave me some hope. I didn't want to spend hours mucking around if the problem was with Shaw.
So I mucked around.
I phoned Tech Support and this person lead me through the diagnostic menus on the 6208 PVR. According to the menu, the ports were activated, but not being used - even when I turned my D-VHS VCR on.
So his conclusion was that the problem was at my end.
I have a simple 6200 HD tuner in my bedroom and did the unthinkable. I unwired my D-VHS VCR from my system (component cables, 2 sets of SVideo input cables, optical audio output, input from old VCR for duping tapes, and the firewire cable). Messy.
I took the D-VHS VCR into the bedroom along with some Component Video cables and its Firewire cable (which is a camcorder Firewire style cable, having asymmetric ends).
After I connected it successfully (I ignored the audio), I got a 1080i video on my bedroom TV. So that meant that the D-VHS VCR was OK.
I then brought it back into the Living Room, went through the pain of reconnecting it and now suddenly the Firewore port is functioning again on the 6208. Don't know why. When the problem first appeared, my VCR did a successful handshake with the 6208, identifying the model number of its display screen, but no audio or video came through. I did a reseating of the Firewire cable too.
OK, I'm happy now. It still works and I am able to record 1080i with DD 5.1 audio. Interestingly, when I went through the Interface/Ports menu on the box, which had 4 pages, on one page for the Firewire port was the notation, "HDCP Off". A good sign.