Huh. I'm not quite sure what they're doing, but they're doing something stupid... (rescaling? But why?).
(book is straight from the fb, screen_02 is Kobo's snap).
(And that's only the very top of the page, it gets more and more obvious the farther you go down the page, but at least at the top you have the 11 black pixels to confirm that the two are indeed aligned).
EDIT: Hah. I'm stupid. 1429 == 1440 - 11. It appears that instead of *cropping* the top 11 pixels off, they're keeping them, but scaling to a resolution of width by height -11...

. Close, but no cigar, nice try ;p.
EDITē: I'd be curious to see what happens with a screenshot taken on an Aura... I'm tweaking FBGrab to handle the cropping automagically, and I'd like to use a sane value for the Aura

.