Ebook images and text far too compressed in ADE

So I've recently had a strange problem when borrowing books from Archive.org/the Open Library--I've already asked them, BTW, and the problem doesn't seem to be on their end. In that whenever I download a book as a PDF, the images become horribly compressed and pixellated and the text as well, and there's no way I've found to get around the situation. Here's an example on a book I was reading a while ago (a book on Old Hollywood child actors, very lavishly illustrated, so the compression problem was really annoying).

This is what the image looks like in my browser, and the data they actually send out from Archive.org when you borrow the book:

And this is what it looks like when I read the downloaded PDF that's come to me through ADE:

I asked a guy over at Archive.org and he gave me screenshots of when he downloaded one of their books to read on ADE, and he didn't have the same problem--the pages looked fine and the images weren't overly compressed. So it's not the data they're sending, but the problem seems to be at my end.

Is there a setting I've missed where I could fix this, just in case I've clicked on something I shouldn't have? I use Acrobat 9 Pro and ADE 4.5.

If there's an older version of ADE I could download anywhere, I'd be grateful for a link. This problem only started recently, and I had an older version in use before.

Thanks in advance!