[ODE] Tri-mesh problem with collisions

[Tristan McMillan]

Hi

I'm a relative newbie to ODE and I've being medaling with the Tri-mesh
function.

I have now drawn a truck in 3d studio max and exported the vertex and
index co-ordinates points which I read into my modified code of the test
trimesh example. However the first tri-mesh truck doesn't penetrate the
ground, but when I drop subsequent trucks on top of the original they
penetrate  the truck to a certain extent and then they fall through the
ground.

Are there any more explicit tutorials on the tri-mesh function and does
anyone have any ideas what could be generating this problem.

Thanks
Tristan