There are only a few things that would cause your sail to jamb. First is the angle of the boom. Release the vang and set the topping
lift so the angle from the boom to the
mast is 90 degrees. Secondly is the
halyard tension. This needs to be just sufficient to remove all wrinkles from the luff. Too tight or too loose and the sail will not furl properly. Lastly is the
boat must be headed into the
wind. I have found that the sail will bind if the bow is not into the
wind even if the main sheet is released so the boom is parallel with the wind but the wind is across the
deck.
You may want to search the pages of the 393 Yahoo group site
beneteau393 : Beneteau393 Group