Well I just used Encore to build direct to DVD so unfortunately I can rule those programs out but it is exactly the same issue. Basically that video clip I posted was from a little portable player which is pretty new but the same happens on my set top minus that black line at the bottom.
You are correct in guessing that there is no issue on software player on my 4:3 monitor. I’m going to make my menu black temporarily to see what effect that has.
Thanks for you help btw.