I notice that when I use the PhysX engine to move an object, the EVENT_ENTITY never triggers despite saying in the documentation that it also responds to "physics entity movement".

Consider the following code (download demo):
Code:
#include <acknex.h>
#include <ackphysx.h>

function ball_event(){
	beep();
}

action ball(){
	my.emask |= ENABLE_ENTITY;
	my.event = ball_event;
	pXent_settype (me, PH_RIGID, PH_SPHERE); // set the physics entity type
	pXent_setfriction (me,50); // set the friction on the ground
	pXent_setdamping (me,10,10); // set the damping
	pXent_setelasticity (me,50); // set the elasticity
	
	while(1){
		//c_move(me,nullvector,vector(time_step,0,0),GLIDE);
		pXent_addforcecentral(me,vector(time_step,0,0));
		wait(1);
	}
}

action hero(){
	player = me;
	while(1){
		vec_set(camera.x, my.x);
		camera.pan = my.pan;
		c_move(me,vector(key_w-key_s,key_a-key_d,0),nullvector,GLIDE);
		wait(1);
	}
}

void main() {
	physX_open();
	level_load("level1.wmb");
}
When the ball collides with the player using c_move, the event is triggered and a beep is heard. When PhysX is used, the event is not triggered. How can I trigger an EVENT_ENTITY using PhysX?