I just crashed while using the resonant exchanger. I have a wall of stone I wanted to remove. I thought, since vanilla MC physics apply here as well, that I could exchange an entire wall from stone to string and have the blocks (string) have a block update. Well, ever since shift clicking the string with the exchanger, I have crashed. I can make it into the game all right. I can click off the screen while the world loads. It's just when I am actually in-game, as in not paused that it crashes. Here is the report: (it's kind of long) http://paste.ubuntu.com/9828101/