Netflix via Oppo

Hi,

I have recently purchaded an Oppo 105 Blu-ray player and connected it to our Pioneer pdp-428xd plasma. The Oppo is supposed to have just about the best picture quality on the market and on blu-ray and dvd it is great. However, when looking at streamed video from Netflix via the Oppo the picture quality is substantially inferior to watching the same program via Apple TV. The Apple TV seems to be 'transmitting' to the TV at 720p. 

Am I doing something wrong? Should the output from the Oppo be adjusted? How?

The Pioneer plasma seems to be able to accept just about any format ( I believe it is 'HD Ready') ans the Oppo seems able to output just about any format.

I would be gratefull for some suggestions.

Best regards

Hans