I have a Humax Aura PVR and Samsung QE48S90D TV which, up until now, have worked OK. However, I do have one major problem, especially when using iPlayer or the like. The picture, as viewed on the TV, is too big for the TV screen and only seems to show about 75% of the picture. If I bypass the PVR and watch iPlayer directly on the TV, the picture is correct.

Can you please advise what course of action I should be taking, or what settings I need to alter, to rectify this problem?