Some of the older IMF sails were either cut too long by the various
sail makers or were not mounted high enough on their tube. IMF works
perfectly every time.
The one suggestion that the boom should be horizontal or even
slightly lowered is correct for sails that are too big. Also,
heading into the wind with the boom slightly off to the starboard is
the best angle for furling and unfurling.
One solution to the problem of furling and unfurling the main that
I've found is to make sure the boom is horizontal...don't release it
until the sail is. My sail is wrinkled on the bottom also...if
anyone has a solution.