to be honest i cant see why having both beams on is a failier, what difference does it make eeerrr none exept if the dip goes out with high beam on, then how the hell can you see the road in front of you, yeh sure you can see half mile away, what good is that
It turns ut that one of the bulbs were put in upside down. This threw the light pattern out which the MOT tester assumed was as a result of both bulbs being illuminated rather than misalignment of the bulb.