Tough luck on the diff, Kiwi.
I thought they sorted that problem too........
I am also heartened to see you are using the 'mag' style rims. Mine came with them, and being used to wire rims I was concerned. I know you use your bike as a real dual purpose, so they must be up to the test.
I get a little worried when they say the diff is non servicable. I would really like to change oils after deep water crossings etc.
Keep us posted.
Gonz.