Yeah - more than likely the plastic drum on the in-mast winch is worn out. It's a common problem.Thanks for the reply sail sfbay. Just one note, the rope clutches on the cabin top do not slip.
I am guessing that it slipping at the drum at the mast, but have not seen it so can't confirm.
Replacing the furling line might help.
Right now I am mainly wondering if this is common/expected and the ratchet is the solution or if I should be looking deeper.
Also keep in mind, if you have Spinlock clutches - to ALWAYS keep them at the semi-engaged position when pulling line in/through. If you have them 'clamped' you are wearing out the plastic teeth in the clutch and not so much your rope/line. With the semi-engaged position there will be light spring pressure and 'about enough' to not let line go out while hauling in lots of it with light loads. With fully engaged - you are just wearing out the equipment.
Same goes for handling the drum in the main mast furling winch.