Sounds like a weak battery Dave, the clicking noise will be the starter motor relay just clicking in and out. You've almost certainly got a gel battery and they can sometimes be unreliable - should be able to get it changed under warranty if it's duff though.
Depends how far you ride as well - If you're starting it but only running a couple of miles between starts the charging system might not have enough time to do it's bit and the battery will gradually wear down.