Problem with Project Format 2K 1998x1080

With Project Format 2k 1998x1080, Color Space RGB 709 and using codec for render DNXhR 444, my Avid (8.4.5) generates a little band with different LUMA on the right of the screen. If I don't render, no band appears! Moreover if I export using codec DNXhr 444, in the file on Luma Band some coloured pixel appears! If I change format project in 2k 2048x858, there isn't any problem!

Any help?