I've had no problems running Ultra in wet clutches. As herb mentions I've used it in his bike.
I only use Shell, so i'm a little biased
but either Ultra (fully synth) or VSX (semi) will be OK.
The 2V are ok on either 10W/40 or 15W/50 as the 15W is tough to get a hold of.
The points that Carbon make are very valid.
Before you start looking at the oil, check your clutch is OK to. Even having used the "wrong" oil could've buggered it??????? or it could just be worn, especially if it's been slipping for some time.