Thank you for your fast answer.
I thought it was the opposite. I mean that the parked frame (in pause) only show one field, and during playback the whole frame was revealed.
Perhaps I am a bit paranoid with image resolution. But I cannot believe that what I see at my monitors is normal avid behavior. I have an ancient Film Composer since 1994 (and still use it), and the quality of the image in the composer window is almost as good as the actual one.
Excuse my insistence, but