My mp4 audio books would not sync at first either. I had to click the box that says "sync all books" or something like that. Then they sync up fine.Hi guys. For the past 2 days I've been getting so frustrated with this iTunes thing and iPhone thing! I've been getting the same problems you've been getting Wim. I have the 3gs, everything was working fine till I upgraded to the new OS. I used to have all my audiobooks synced on the iPhone. Now, iTunes doesn't even recognize the files. They're there, I can listen to them and change the settings but they just don't sync. I can say that the file type has nothing to do with it or Audible.com settings. I blame it on the new OS.
Now I'm bored at work... Can't listen to my audiobooks.
Oh man, do I feel stupid. That was totally it. Way to hide it iTunes. It was burning me up for hours!I just wanted to let you guys know I was having the same problem and found a solution on another blog:
While my phone is attached to iTunes and selected, I'm looking at all those tabs. I click on the "books" tab. ....Hope that helps - i know it has been driving me crazy!
scroll down... past the fine print that says "download the ibooks application from the iTunes App Store to read books on your iPhone", to the SECOND checkbox next to "Sync Audiobooks".