Audiobook files do not play correctly in iOS 5 I upgraded to iOS 5 on my iPhone 4 and now I cannot play audiobooks correctly.  When I transfer audiobooks to my phone using Overdrive they show up in the book section but are unable to play.  I have to designate each file as Music to be able to play them, but then I am not able to listen to them in chapter format, nor am I able to play in double speed or use the 30 second fast forward button.  I spend more time listening to books on my phone than anything else so this is a major digression in capability.

Is there a fix to this?
I had a similar issue with the default music app and the Steve Jobs biography audiobook (ironically).

I had to manually delete the audiobook from my device by checking the box for Manually manage music and videos in iTunes, then delete the files, then re-add them again.

Have a look at the audiobook entries under your device in iTunes - mine had a sync icon next to them as if to indicate that the problem was getting them onto the device, rather than with the player itself.

I haven't yet tried to uncheck the box for Manually manage music and videos for fear of breaking the audiobook again.