I have found when sailing the Topper Xenon the slug at the bottom of the main-sail has a tendancy to pop out of the runner in the mast - the result is flappy, vibrating foot on the main sail (see http://wivenhoe-sailing.blogspot.com/2009/07/parts-of-sail.html). Whether this makes any difference or not is hard to know, but it is very annoying when you're bombing along. Maybe it's me but I tend to have the Cunningham right off when sailing round Wivenhoe to get as much curve in the luff as possible. With recent light winds it has been essential - this hasjust made the popping out slug worse.
The solution I have come up with is best described in the picture below. The Cunningham once threaded back through the boom and locked off, is lead-up to the bottom tack. When doing this it is important not to prevent the cunningham working or you will not win races....
