Well I sort of figured this out - while WMC doesn't properly detect QAM channels and requires me to manually add them; WinTV usually scans and picks them all up properly. Some channels would tune in with a new physical number and then would go right back to the old physical number and not tune anymore. Some would never display a new physical number. Out of the ones that would tune - I noticed on the physical channels, all the sub numbers were the same as before; while the primary numbers all now fell between 20-39. So I basically had to create 20 diff numbered channels for each individual channel and see which would tune. It was time consuming, but it worked and I now have all my channels back with the proper physical numbers. Whether WinTV is the problem, not picking up the correct sub numbers - or if it's something in the signal coming from my provider, I don't know. I will contact Hauppage and let them know of all this but after dealing with their support, I don't expect anything to come from it.