solved it for the time being at least mate.
i swapped round all my hdmi connections, well 3 of them had the square on hdmi 2 hdmi 3, plugged it into hdmi 1 and the square dissappeared, if this helps it's a 4K 60hz DVI port (dont ask mate i dont know either) lol.
regards: canthackit
Thanks mate, swapped from HDMI 4 to HDMI 3 and now the white square has gone.