Example: https://www.dropbox.com/s/r87728wmwhhqnpm/example.capx
controls: click with the mouse and the black ball will move to that position, try to collide with the little ball next to the wall.
The problem occurs when a ball is next to a wall, in this case, the ball never leaves the wall when other balls collide with them.
The thing is that this is not a rare situation, it occurs often, there is any parameter for fix this problem?
Thanks in advance.