I bought a pair of Mach 1 wheels from PlanetX that said the hub was compatible with Shimano 8/9/10 speed. When I tried to install my 10 speed Tiagra 4700 cassette it doesn't seem to go down far enough on the hub. PlanetX just said if it doesn't fit you can return it but should it not fit? It looks like it should but maybe I'm missing something?
I have experienced this exact problem except trying to fit a 4600 cassette on the same hub.
If you look at the cone, you will notice the threads expand slightly nearer the centre at the point at which they start to stick.
I will update this answer if I ever get a clear explanation for this design feature.
Update: lbs got it on with some brute force! Presumably a one way road? Will update if it goes badly wrong.