When my new board turned up from Odyssey with a long button I was confused (this was before they'd announced the Z board, so it must be one of the first - doesn't even have a Z code on the back
) so I emailed them back and they popped a sticker (with the little raised dimple for the button) in the post. Remove the rubber button from the back plate, put the sticker on (nice and square now) and
voila!