Physics.IgnoreCollision not work

Collider cld0=move_cube.GetComponent(“BoxCollider”).collider as Collider;
Collider cld1=tan.GetComponent(“BoxCollider”).collider as Collider;

Physics.IgnoreCollision(cld1,cld0);

but Collision also happened.

Thanks.

Perhaps try using the new collision matrix
http://unity3d.com/support/documentation/Components/Layer%20Based%20Collision%20detection.html

Thanks