This furling system consists of a continuous loop 7/16 inch line that engages a "drive sheave" that is inside the roller furling drum. My problem is that when partially reefed in higher winds, the sheave slips around the furling line and the 150% genny is all the way out. I have the line cleated tightly in the cockpit with all of the slack removed. Line doesn't seem worn. Any suggestions? (1991 C30 Hull# 5945)