Try changing the Monitor's display from Both Field to First or Second.
Thanks so much for getting back to me. Unfortunately this doesn't seem to help the issue. I've toggled both monitors to First Field, and it doesn't work. I think at this stage, I've tried most options I can think of and I would like to try and get a standard project setting that is designed to work with this material [ProRes 422 HQ 25fps 1080 at 50i] from the get go. As I say, it works no bother in FCP 7, without any settings being adjusted, but for whatever reason, Premiere CS6 and the latest version of QuickTime play the material back "Jagged", ie with both fields.
Would really appreciate any logical diagnostic tests to take to find out what's happening here.
What does it look like when you fullscreen the Program monitor? (CTRL+` on the PC, not sure on the Mac.)