I tried my AVR-X2300W with the display suite firmware and the results were interesting. In AVR bypass mode, 480i resulted to no signal (576i was ok) but with Denon’s scaler enabled, 480i was displayed correctly. This needs some investigation. One different thing with DVD 480i sources is that they use YCbCr mode instead of RGB, perhaps you could try YCbCr444 TX mode in the most recent fw. I’ll see next if it makes any difference if some Infoframe parameters are tweaked.