This is the captain speaking:

Of course seaman Lowe is correct when he says you want the sail coming 
out of its mast slot as  cleanly as it can.  The way to do that is to be 
into the wind so the boom is modestly off to starboard. BUT, a more 
telling issue is (I know when I interject this kind of nautical fact it 
ruffles a few feathers, so I generally don't, but I am in a good mood 
today.)  IMF sails should be obtained from the GB parts site  
www.rhodes22parts.com  because the GB IMF sallysail main is a 
proprietary cut designed to function with the GB IMF furling system 
(which, incidentally. has self lubricating bearings.   If a GB IMF main 
is not working, something is being done wrong or some part has failed.  
Either case can be remedied.  Putting a downward pressure on the boom is 
not one of them.