Thanks, ill have another look. The lamp didn't go in easily, so ill have to try and take it out and check and refit etc. Its likely the ballast in the way and catching, as I mounted both ballasts on the underside of the lamp unit. In fact, it might be that the screw that mounts the ballasts may be catching and preventing the adjustment moving freely (didn't have time to cut down the screws as was going dark and needed to finish) so will remove and shorten them in case that's the issue. Just a shame you have to faff about with removing the bumper (poor design in my eyes).