[away3d] Away3D Collision using Jiglib beginner problem

[Dona]

Hi,

I've created terrain and collision objects in away3D(flash sdk cs5)
for a racing game.Now i'm trying to create collision there.But i'm a
very beginner in jiglib physics.Whenever i'm applying step function in
enterframe function then i can see, the angle of the terrain is
totally reversed...

I've created a hovercamera and following are the setting.

protected function setCamera() : void{
            camera.zoom = 1;
            camera.focus = 600;
            camera.targetpanangle = 180;
            camera.targettiltangle = 8;
}

And I've created terrain here...

private function createTerrain() : void {
            var ground:RigidBody = physics.createGround( { width:2500,
height:3125, segments:20 } , 0);
            physics.getMesh(ground).material = new
BitmapMaterial(Cast.bitmap("Terrain"));

  }

protected var physics:Away3DPhysics = new Away3DPhysics(view, 5);

I appreciate all your help
Thank You