Flying Pram,
I think that you will find that I mentioned "Dual" Training and there is no dual training requirement or test in navigation to de-restrict a microlight rating.
DFC, From the "Microlight Pilot's Handbook" (the U.K. "bible" for microlight students):
Types of Group D Licence
Restricted - A minimum of 15 hrs flying instruction of which 7 hrs must be solo. The solo hours must be completed within the 9 month period prior to applying for the licence.
Unrestricted - In addition obtain a further 10 hrs flying time of which at least 5 hrs must be navigation training under instructor supervision.
Complete 2 solo X country flights of at least 40nm over different routes.
During each flight an out landing must be made at least 15nm from the take off point.