Do they have customer service number or email address you can contact?
I contacted their customer service yesterday and finally got a reply today. I had to send them screenshots of the error and my PDF properties which their tech team will "look into".
I'm not familiar with Blurb, but I have used Amazon's Createspace and KDP, I guess it's a similar process. If you originally saved it as another version and tried to upload it and then saved it again as the correct version (overwriting the same file), sometimes you just have to rename that file and refresh the page before uploading. Sounds a bit silly but it's worked for me when I've had similar difficulties.
I finally managed to get through pre-flight by uploading using their InDesign plugin. God knows what that does differently that their preset doesn't, but oh well.
Quick question: Would you recommend Blurb for Self-Publishers?
Absolutely not. Their service is poor, the site is clunky and awkward to use, information you need is not available or simply hard to find, though I suspect that's just me not wanting to send business their way after my awful experience. I guess it's the case with most POD services. Plus you never know how the books will look until you pay full-price for a proof and have a look. In the past I've had to have up to three attempts to get a book right, which obviously the client wasn't too pleased about. This book I'm doing now is over £70 per copy, not including shipping!
Personally I'd recommend anyone wanting to get a single copy of a book printed, to just use a decent printer to do the pages and pay a book-binder to put it together properly. It will probably be cheaper in the long-run.
