Steve Hillary at MotoRapido has fitted Gates P/No belts to my bike in the past...I don't know if he still does.
I have never had a prob with them (2 yr or 6K miles are my limits).

There wont be any problems because they are exactly the same thing as the ducati branded ones. made in the same factory on the same machinery. So unless the ink they use to print ducati on them makes them stronger there will be no problem. In fact up untill 1999 they didnt print Ducati on them, the ones I took off dont have Ducati printed on them, hence there should have been a catostrophic failiure by now.