Oh Oh... one other thing to try. Try releasing some rig tension. But remember to mark the nut positions on the rigging
screws first with a permanent marker- then you know how far to re-tighten them.
But by slacking off the rig, you may find it eases any tention if its a swivel jam for instance.
The big thing to remember is that it should never be hard to hoist a sail on a small boat like yours. If it is, you have a problem. Next time drop the half hoisted sail and find out whats causing it. Hmm.. i wonder if the track has been crushed somewhat by a previous owner. Thats something else to check for..