I recently added fuel to my Model V Vixen. Returning to the hangar the next day, I was informed that fuel was leaking from the airplane. On inspection, both tanks were bone dry. I looked at the sight glasses, and found both were loose, although the retaining nuts (plastic, holding the plastic sight glass tubes tight to the tanks at the top and bottom of the sight glasses on both sides of the wing root) were tight. I have never been happy with the original arrangement. Has anyone else had trouble with the sight glass configuration? Done something to improve or fix them? My airplane is not flying until this is resolved.