Since so many people are coming to this blog for news of the Google Books downloading problem — Free Google Books Ends Downloads (it’s a glitch) — I’ve made a separate Sticky.
Second (Final?) Update, Tuesday March 13, 2012:
As of 9PM EDST, I can also confirm what these Commenters reported:
Mine are all working now, although with one of them I had to try twice in succession before it worked.
Works for me now – checked after getting an email from someone at Google saying it had been resolved. Now to download everything I think I might possibly ever need…
I downloaded my usual test PDF as well as two random ones and they all came down intact and in full. I confirmed it by looking at them in PDF-reading app.
First Update, Tuesday March 13, 2012: According to a Commenter at the original post, who spoke to Google via phone:
I received two follow-up emails as well, the last saying “Our engineering team has identified the problem and are working to resolve it quickly. While I cannot offer you an exact timeframe as to when it will be fixed, I will email you as soon as I have an update.”
It must be some catastrophic screw-up for it to take this long to fix. As of ~8:30AM EDST, I am getting Whale Fail when I am past the CAPTCHA for a PDF download.
My advice to everyone: Once this has been fixed, set aside time to download every damn Google Book you’ve been delaying.