Just to save anyone else the hassle - my mate rode my DCT to try it out yesterday. When he had left, I jumped on to put it away & it wouldn't start. The hyphen type icon on the dash (which is supposed to go out after a couple of seconds) was flashing & nothing happened when pressing the start button. Checked the owners manual & it said there was a gearbox fault. Got the AA out & prepared to get the bike to the dealers.
After disconnecting the battery which didn't cure the fault, the AA man noticed the cut out switch was on. Flicked it off & the bike started normally.
Would be good if it mentioned in the troubleshooting guide that should be the first thing to check. Doh!