how do I re-download or find my previously purchased audiobook?

You cannot redownload audiobooks.

It is your responsibility to back up your content.

Did you fail to import all itunes purchases to your computer before updating?

"I use iCloud for backup,"

Audiobook industry does not allow redownload, so icloud does not back them up.

"

Here’s what iCloud backs up:

• Purchased history for music, movies, TV shows, apps, and booksYour iCloud backup includes information about the content you have purchased, but not the purchased content itself. When you restore from an iCloud backup, your purchased content is automatically downloaded from the iTunes Store, App Store, or iBooks Store. Automatic downloading is based on iTunes in the Cloud availability by country, and previous purchases may be unavailable if they have been refunded or are no longer available in the store.
• Photos and videos in your Camera Roll
• Device settings
• App data
• Home screen and app organization
• iMessage, text (SMS), and MMS messages
• Ringtones
• Visual Voicemail"

http://support.apple.com/kb/PH12519?viewlocale=en_US

"Where would there be a warning saying that there is only one time download for audiobooks?"

historically, ALL content was one time download. Over the last year some content has been made available for redownload. Nothing has changed with audiobooks. They are still one time only.

Using icloud as your sole back up is not a good idea. There is no guarantee that any of your purchases will be available for redownload ( for example if the song/movie, etc ic no longer carried by itunes).

You should always maintain your own backup copy.

You can try

i download and redownload everything i buy on audible. different industry? or beter user experience? i agree with the poster above. the good lesson learned is dont buy anymore itunes audio books. I learned the same lesson with video years ago. 300+ tv seasons from amazon later, itunes still hasnt much improved their video experience. so far, itunes is only best for music (11000+ songs and counting) trolls refrain from shaming me about my media habits.

When ever I have had to do a OS update I have always had to take books and music off my phone to be able to get the download. And I have always recovered my Audiobooks on the cloud. This latest OSI7 upgrade will not let me get them back. Sorry but if Itunes isnt not smart enough to verify my devices and that I am not selling my downloaded material to the Russian Mob I have a problem. My audiobooks got me through a record setting winter here in Detroit plowing snow. Please resolve this and return my books. Mostly Biography"s. Not to mention the one Audibook that did not get bounced it would not allow me to acces it until i hooked it up directly with my computer. So much for the terms Idiot Proof and Plug and Play.

I too had this problem. My wife download of a book from iTunes and the download failed halfway through. No way to re-download without contacting support and jumping through hoops and then maybe they will let you re-download. Not sure where the industry standard claim to not allow books to be re-downloaded came from. Audible.com lets me re-download as many times as I want. I think it is a ploy. I will only use amazon and audible now to avoid the hassle.