Sorry, when I said "jib preventer" I meant poling out the jib, which I've never done.
Yes, in this case I am always doing DDW. I find that in light winds, say if my boom is on starboard, and I turn to starboard just by 10 degrees this causes an accidental gybe.
By jerking I mean, it the boom comes aft and forward in a violent kind of way, espcially if we go over a wake or over a wave. This usually happens in lighter winds.