When we had our problem and technicians checked signal strength, it was always DURING THE DAY when they made their tests, but they never checked signal strength in the EVENING. Pixelation would start with the arrival of prime time around 6:30 -7:00, then get worse, reaching the absolute worst around 9:30, then get better after 11:00 or 11:30. The PVR worked fine recording during the daytime but went to hell recording in the evening,the same as direct play. I suppose there could be a problem with recorded programs due to an issue with the record function of your PVR, but If the PVR works fine in daytime but has problems at night, then the problem is with the incoming signal, not with the PVR.
So check: is it a prime time issue or does the image still pixelate during the day or early morning when few people are watching TV?. Are any of your neighbours having the same problem? If it is a prime-time issue and your neighbours on Shaw have the same problem, then the problem is not with your cables and equipment but with Shaw's system. They solved the problem in our neighbourhood when they replaced some sort of distribution equipment in a box out on the street. I assume it was some sort of amplifier that boosted the signal going out to the neighbourhood. The real problem is with Shaw management: Their customer service, technical inspectors and system management do not communicate. The result is that they waste a lot of money attempting to "solve" problems within the scope of their work, but never consider the possibility that the problem lies in a different part of the system than what they are responsible for.
It is also possible that they are able to convince some customers to subscribe to a more costly service by their failure to resolve the issue and feel that that is an accomplishment - but I ascribe the problem to incompetent management
