I got mine in seperate amounts... it didnt all come in one big amount.

I got my TAX back in one amount, then the next day I got my FTB and CCB.. I'm not sure if it always comes the next day for everyone, maybe it doesnt and you'll be reciving it shortly.

Did they send you a letter as well to tell you how much you would recieve and what it is for? Maybe the extra is your CCB, or the quarterly CC taxrebate?

Do you use the online system for FAO/Centrelink? If you do, I'm pretty sure you can log on and see when your payments are due.