Half Blood Prince: two sentences missing from UK edition

[Tim Regan]

No: HPFGUIDX 135437

Hi All,

I'm at Accio 2005 and heard from Troels Forchhammer via Ali Hewison a
very strange omission in the UK version of Harry Potter and the Half
Blood Prince. Dumbledore is back from drinking that awful potion and he
is in his office trying to persuade Malfoy to repent. 

Here's what he says in the UK edition:

<<< What is more, I can send members of the Order to your mother tonight
to hide her likewise. Your father is safe at the moment in Azkaban ...
>>>

In the USA edition there are two addition sentences between those two,
the latter one sees Dumbledore suggesting that the Order could fake
Narcissa's abduction and death since the Death Eaters would be expecting
it. (Sorry, I didn't bring a USA edition back up to my room to
transcribe.)

I can understand language changes, but why would Bloomsbury cut two
sentences, or Scholastic add them?

Cheers,

Dumbledad.