I also have learned that when i ease the main out to the point the boat comes unstable I can kind of balance it by pulling in the main or easing it based on the rocking motion. I just counteract the rocking with pumping the main.
Sail by the lee and kiss death rolling goodbye.
Sailing dead downwind is a bit like watching a flag fluttering in the breeze. The wind flow moves it one way and then the other. In a similar way if you sail dead downwind, the flow over the sail alternates from leach to luff and luff to leach making the boat almost impossible to control.
(read Steve's article for the reason this works!The common running problem is the violent roll to windward that causes the boat to start to bear away radically. What do you do? Perhaps you pull the sheet in and move your weight to correct the trim, but lets concentrate on the rudder. Do you push the rudder away from you (head up) or pull it toward you (bear away)? For most of you it is probably inconceivable to pull it towards you, but that is actually the right answer!
Check out my avatar. This is my DW positioning in nearly all breezes. Feet against the front/inside wall of the cockpit so I can push back if I wanted and with my feet against the wall I can pull my weight in to counter a roll. I also pull straight up with my arms when trimming and trim from the block. If you pull out or trim directly from the boom it will initiate a rolling affect as you are moving your weight outboard.