1. the vertex struct changed with 7.05.1. are you sure your engine version isn't older? i don't have any other explanation.

2. i haven't tried the double precision dll with lite-c myself yet. i would have to experiment with this. but since the double precision dll works with other compilers it must be some issue on the lite-c side. i think lite-c automatically casts floats to double when needed but i am not sure. you could try to directly use doubles for everything.

3. my pool game uses the old gamestudio plugin and there julio jerez added the dryrollingfriction for me. for lite-c you have to adapt the custom joint example.

@vet: i am not sure what you want to achieve.