I did find that I could overcome it by just getting bigger and bigger with the angles. ie. specifying 352 degrees say, then 380 degrees, then 420 degrees etc. It seems to work.
But I actually used a suggestion Aerilius made, which was to get to 359, then do a change to 0 with a duration of 0 so it spun anticlockwise infinitely fast, then carried on with 20 degrees, 80 degrees etc. That also works.
But it is all a fudge. Surely there is some way of forcing the rotation to the desired direction.