Cheers Stu - and guys for the tips.
Took it all apart and had a play with it, still spins badly, tried reseating it many times.
All I can see when it's apart is the spring is out of bonk. When I stand the spring on the bench it's lopsided, the flat ends are not aligned with the springy middle bit ! Maybe this isn't helping ?
I'll just not use it and bring it to a meeting
