Stacking

[Neversoft]

Ok, well. My rooms arnt letting me stack. I can't stack in any of them.. I had a really good room idea now its ruined because I can't stack. I tryed the Roller stacking because thats like one of the only stacking you can do without it being up against a wall, it worked at first. Now has totally stopped. Does this happen to anyone else?

Also, how the hell did he make that! :'(
http://img153.imageshack.us/img153/1453/untitled4ow.png (http://imageshack.us)