Thanks folks for an interesting set of replies. Now i'm not renowned for my logic, however its strange that it didn't happen for the first 3500 miles so don't see how dropping the forks or changing banjo bolt will work. Its not glazed pads from gentle braking either.
I certainly wouldn't let it put me off buying a Multilooney.
Its done it for the last 3000+ miles all the way on holiday and back. Maybe i'll ask the dealer for a new Ohlins equipped MultiS as a warranty claim to solve the prob
Certainly will try the banjo when it goes for service and let you know if theres any improvement.