Could the airflow in powder toy get fixed up because as you can see in this http://www.powdertoy.co.uk/Browse/View.html?ID=144627 Just remove the wall and you will see that the high pressured outside doesn't flood into the vacuumed bit on the inside.
For some reason it did not save the fact that the pressure is -100 or something and if you just remove a bit of the wall you would expect it to implode in really quickly . Not really slowly like it does at the moment.