Originally posted by Bob B
Check everything else first! My clutch was slipping while under load also and I thought the clutch was bad. It was actually nothing - a $25.00 fix. There is a rather complex pin assembly between the clutch lever and the master cylinder that was simply binding on my bike. My clutch lever had worn (from lack of lubricant - bad me) and the pin was binding.

Thanks Bob will check this out
I haven't got to a dealer yet as its a bit cold here for 60 miles one way but am planning on keeping a close eye on what they do, as they do it