Hey !!! I've got the english edition (the spanish has not been published, we still and still and still have to wait until February 23rd), from Bloomsbury, page 552, and I don't have that line either ..."He cannot kill you if you're already dead", but after reading all your post I realized I don't have these other lines:

Nobody would be surprised that you had died in
your attempt to kill me -- forgive me, but Lord Voldemort
probably expects it. Nor would the Death Eaters be
surprised that we had captured and killed your mother --
it is what they would do themselves, after all.

Why do they do this? do I have to buy the books at the US to have the complete book ? Are we missing something important? I'm really disappointed!!!