It definitely says 3 months each visit. I am not sure if its a 976 to be honest, I will have to check (am asking for a friend). I think also either checking with Immi or on arrival is a good idea, as I want to book flights back out of the country, etc and dont want to be penalised for having to change flights, or worse, overstaying the visa. I'd really hope though that give or take 1 day over the period of 3 months, i.e. 11th Sep to 9th Dec is acceptable to a normal Immi office at the airport!
Thanks for your reply.