I have read somewhere that someone had good results with the original hub when he tapped a 4/40 thread and used a 4/40 screw instead of the original 2/56 screw. It seemd to have cured the problem of a loose hub.
Instead of the 4/40 you might use 3mm screw instead to stay with an all metric screwsize. Not sure if there is enough material on that side of the hub though but might be worth trying out.