[ODE] Sphere/Plane friction

[Robert Rose]

Hi all, I'm trying to get back into ODE.  Right now I'm trying to write 
a simple simulation of a ball hitting the floor and rolling around... 
I'm doing this using a plane and a sphere.  My problem is when the ball 
hits the floor it never stops rolling.  Here's my collision code:

if(dCollide(spheregeom, planegeom, NULL, contactgeom, NULL))
{
   dSurfaceParameters surfaceb;
   surfaceb.mode = dContactBounce;
   surfaceb.mu = 50.0f;
   surfaceb.bounce = 0.6f;
   surfaceb.bounce_vel = 0.01;
   ...
}

?
-robert