Received an email from FFG saying the rulebook had been updated this morning, so I go back to RPGNow to download again and it claims its a 207mb file. Assuming this was the update (+70mb) i download it again, but it turns out to be only 130mb still, and no updates that I can see in the book.

Ugh, that was terribly rambling. Anyway, the question I wish to ask is has anyone else had this problem/I'm going insane?

I don't purchase digital copies of books, but the news article about it being released was only yesterday - maybe that's all it is?

Updated with what? Fixes to the spelling/rules that are broken?

I don't know, hence the question. I just received an email that said:

Updated PDF for Black Crusade is now available.

Please let us know once you get the updated one. if it has fixes to the rules i'll probably purchase the download version.

It's more than likely just fixing any problems with images, fonts, etc. FFG has always released an errata months before releasing any updated rulebooks, so the lack of a released errata would suggest that no rules changes would be included.