Two things come to mind. First, does your jib
head go up close to the mast ? If the luft is too short you are getting halyard wrap. To fix the problem add a length of pennant to the bottom at the tack so that you can raise the jib
higher. Second, check that the angle of the jib
halyard to the mast is correct. If the halyard is too close to the reefing foil you could get wrap.