Regulus Black is mentioned three times in chapters 1-6 as being Sirius' younger brother. Do you think this means that he is R.A.B., or might it be Rowling throwing us off?
Was I the only one who whilst reading HBP was reminded of The da Vinci Code where instead of "a pope", it was "A. Pope"? As in instead of being a "half-blood prince", he's a "half-blood Prince"?
The cover of the US edition shows both Harry wielding his wand in his left hand and also Dumbledore's right hand appears unscathed, whereas in the book it's clearly stated: Dumbledore's right hand was as blackened and dead-looking as it had been on the night he had come to fetch Harry from the Dursleys. (pg 165 US) Do you think Mary GrandPré meant it to be mirrored, or was it a mistake?