Notts is my local dealer mate, they've been good for me so far!
Mine has 59k on the clock but the gear box was swapped by the dealer not long ago but I've still got the clunk, one of the guys on here put it down to a flywheel spinning too quickly or something - do you still get it if you leave the clutch down longer??
To be honest as well mate, I don't really get the problem very often any more, I'll pretty much always get the problem if I start to apply the throttle even slightly before the clutch is released enough but I'm used to it now so it's rare that it clunks too much as I've adjusted my driving slightly.
I think it's a common problem though as lot's of people have it but it's something you'll get used too eventually. If it is really bad then get the dealer to look at it, they swapped my box over but the problem is still there, I'd say it's more pronounced when it's cold though, when she's warmed up it's better..