Volumetric lighting. How to set it?

This is really ahem:

import direct.directbase.DirectStart
from pandac.PandaModules import *
from direct.filter.CommonFilters import CommonFilters
alight = AmbientLight('amibent') 
alight.setColor(VBase4(3, 3, 3, 1)) 
alnp = render.attachNewNode(alight)
plight = PointLight('point')
plight.setColor(VBase4(0.8, 0.8, 0.8, 1))
plnp = render.attachNewNode(plight)
plnp.setPos(0, 0, 1)
render.setLight(alnp)
pnda = loader.loadModel("panda")
pnda.reparentTo(plnp)
base.camera.lookAt(pnda)
fltr = CommonFilters(base.win, base.cam)
fltr.setVolumetricLighting(pnda, 32, 5.0, 0.1, 0.1)
run()

EDIT:
almost the same happens with the normal mapping example, maybe my graphics card is not capable for that?

EDIT2:
if the same thing does not happen to you: