Yep, he is right. I tryed it again today and it´s absolutely possible without moving them back. I was just to stupid.
Very nice game, especially with the grate smoke and liquid physics.
Nope. Thats why I commented here, hoping someone would know a solution.
Technically a very nice game, but unfortunately I couldn´t get past the second room, scince for some reason I can only move the floor plates in one direction.