The famous Aprilia clutch slave seal problem ........ your bike was not wanting to return to Athens
The seal from Aprilia is very cheap, but its a pain in the butt to constantly have to think about every possible concern you could have when on a road trip, so for peace of mind and less stress traveling, I would recommend you get an aftermarket clutch slave cylinder. I bought mine on ebay and for 100 Euros had it delivered to my house. I will try to attach a pick of it.
Soto