Audiobook troubles

I downloaded an audiobook from iTunes (One of a series ) only to find that it is missing bookmarks.It shows up in Audiobooks in the library and when I drag it to the Audiobooks on the devices menu. It doesn't show up on the iPod itself in the Audiobooks menu only under artists and Music. I have the other 10 books in the series and they are just fine

This is the 2nd audiobook with the same problem
Any help would be a great as I don't know what to do next.
I have sent a complaint to Apple only to get an e-mail with lots of links

iTunes version 7.0.2. (15) running on
iMac Intel (Late 06 model) with OS 10.4.8

Is it in the podcasts folder?
What ipod do you have?

I have a 60GB ipod Video
No it's not in the podcast folder.

It shows up in the audiobook folder when I have the ipod connected just not on the ipod itself except in the Music and artist folders

Can it be a corrupt audiobook ?
I'll try to download it to my wifes nano to see if there is a difference

Audiobook problems

Go into the iTunes Music folder and see if the file extensions all have .M4b. If they do okay, otehrwise change them to that extension. Then I suggest trying Doug's applescript called "Make Bookmarkable". It works really well in converting audiobooks and getting them to align with the proper folder.

Thanks for the tips and Ideas
In the meantime since I have Applecare for my iMac and iPod I contacted Apple.I had no luck downloading the books to my wifes Nano Which led me to suspect a corrupt file in the Audiobook. The Boffins at Apple agreed with that too. I have since downloaded another Book in the same series and that is fine.