Apparently Zippo lighters needing repair can't be sent in the post anymore, because they might contain fuel.
"Please note: The Royal Mail have recently adopted regulations which classify Zippo lighters as dangerous goods. As a result of this classification any lighters that are sent via Royal Mail services could be returned or destroyed. Zippo UK are working to seek a reclassification of our lighters allowing them to be transported by the Royal Mail".
Bear in mind the Zippo warranty - "it works forever, or we fix it for free" that must be causing problems.