Round about that time Ducati changed the slave cylinder to the larger "cotton bobbin" shape. The first of the new shape were subject to a recall to drill a release hole, otherwise if the seal failed, they could "hydraulic lock". I expect this is what your dealer is talking about.
Desn't sound like that's your problem, though. Like Brent says, I'd take the plates out and examine the outer drum for notching. If it's not too bad you can squeeze a bit more life out of it by carefully dressing the notches smooth with a file. Don't go mad, though.
And removing built-up dust in the clutch doesn't hurt, either.
Hybrid Mode
