My
beneteau 40CC has a very similar
mast and
furler if not identical. When I first bought the
boat I had a similar experence to what you describe. Usually yhe issue is the leach doubles over during
furling due usually to inadequate tension on the
outhaul. This will be compounded by an old baggy sail. Once this happens it is usually a trip up the mast to wrench the overlap free of the fulrling slot.
I replaced my
mainsail 12 months ago and have never had an issue since. There is a usefull article written by a sailor on how to furl properly on the ZSpar website.
Dont be put off the inmast furling. I love it, however there are a lot of armchair experts who run them down. For ease of handling especially if you are short handed they are great. The lack of roach in the main does reduce the sail area and I guess performance a little, however I have never noticed too much of a difference. If one is concerned about deminished performace fit a folding prop. That will easily overcome the difference.
If you are concerned get down to a marina and find a
skipper with in-mast furling and talk to him about it. Chances are that like me he'll love it.