This crops up regularly - make sure it is on the tickets or you have it in writing. If they won't provide it in writing, email agent and/or airline and ask, do I get a 40 kg allowance? If they reply in the affirmative you have it in writing and you take the email with you. As someone said make sure you don't go over because you may just get that 'jobsworth' at check-in who will charge for excess.

OzTennis