A case where c_updatehull is required is when the terrain is deformed and something does a terrain collision within the same frame.
That might have been my problem.
Thought I'veput enough wait(1) all over the code, but maybe I still had a gap somewhere.
But why should colission not work with unchunked terrain in A8?
That's what I'm doing... at least I'm using c_move and c_trace without problems...