[nelly]

sounds like the seal on the slave cylinder piston has gone.
It's pretty common. Check around the back of the slave cylinder and front sprocket for fluid.
Replacement isn't too difficult. You can use either a new Ducati one or an Evoluzione one. The Evo ones has better seals and cost about £3 more at £18.
I stock the Evo ones.
It's far less common but similar symptons can be had from thes eals in the master cylinder failing to.
The fluid will turn black........."they all do that".
I use 5.1 fluid with no problems, so you're OK there.