T - I think most people get the 2 x 1/2tablets daily. Maybe you should call your GP and ask if she can 'confirm' that and give that a shot as well.
I had a look at Aidens charts last night, at 6weeks, he was 4.75kg, I am not sure how much A weighs now, but, I would think it would be ok to give him the 2 x 1/2 tablet dose's. I dont think it is weight related dosage, as Aiden stayed on that dosage right up to 6months. And, A's reflux is worse then Aidens, so, i really feel that he needs more.
Perhaps a GP cant authorise that higher dose amount? Not sure.