physics problem

[fivel_lab]

hey, first time poster here

currently, i'm trying to setup a balance board type apparatus that includes the board, and a ball that rests on the center. the board tilts up and down and is controlled by a wii remote controller. as the board tilts, the ball rolls down accordingly. all that is working fine and dandy, but a problem keeps occuring where the ball suddenly drops through the board, and i haven't been able to figure out why. i've tried playing with the density, bounce, and hardness of both the board and the ball, but still no luck.

here's my script so far:

#create balance board
bar = vizshape.addBox(size=(20, 1,1))
bar.setPosition([0,2,5])
bar.color(1,0,0)
barCollideShape = bar.collideMesh()

#create ball
ball = viz.add('ball.wrl')
ball.setScale([1.5,1.5,1.5])
ball.setPosition([0, 7, 5])
ballCollideShape = ball.collideSphere()

as well as the scrip for the wii remote controls:

#Add wiimote extension
wii = viz.add('wiimote.dle')

#Connect to first available wiimote
w = wii.addWiimote() 
def updateWiiMote():
	w.led = wii.LED_1 | wii.LED_4
	x,y,z = w.getAccel()
	x,y,z = threshIt(x,y,z)

	newEuler = (0,0,-x*10)
	print newEuler
	bar.setEuler(newEuler)
	
	
#poll joystick continuously
vizact.ontimer(0, updateWiiMote)

and i also created "guardrails" in front of and behind the balance board, to keep the ball from rolling off on the z-axis:

#create rear guiderail
farGuiderail = vizshape.addBox([30, 50, .01])
farGuiderail.setPosition([0,2,5.5])
farGuiderailMesh = farGuiderail.collideMesh()
farGuiderail.disable(viz.RENDERING)
farGuiderail.disable(viz.DEPTH_WRITE)

#creat front guiderail
nearGuiderail = vizshape.addBox([30, 50, .01])
nearGuiderail.setPosition([0,2,4.5])
nearGuiderailMesh = nearGuiderail.collideMesh()
nearGuiderail.disable(viz.RENDERING)
nearGuiderail.disable(viz.DEPTH_WRITE)

any help would be greatly appreciated. thanks in advance