Oh, I didn't realize it was this game. The only way I can think of is to move the container away from the player when it collides. It's not perfect though:
ThePusher_Edited2.capx (r99)
The pin behaviour might not be the best thing to use for this game as it doesn't really work well with other behaviours. It kind of overrides the other behaviours like solids. Maybe using custom movement or physics to move the boxes would be better, I don't know.
I'm sorry, but I'm out of ideas on this one. Maybe someone else can come up with a better solution.