yeah, i have the same issue, i don't know whats caused it, neither do honda, mine does pull in and out. but doesn't spin. it also appears that its the only way oil leaks out as well. i have replaced the dipstick tube, iirc only about 15 quid on back order, which was about 4wks. at the moment i've left it, as it doesn't appear to have any detrimental effect, apart from topping the oil up with fresh, which isn't a bad thing...