What were you doing exactly? I have no experience with apple devices but I try to help. ^^;
Generally speaking audio books are just audio files (mostly in .mp3 format, and parted by chapter) so any device that can play audio files (mp3 music) should be able to play them.
If it does not belong anywhere else and has to do with iPad post it here.
Thanks for the reply and trying to help. I click on the link to download the audiobook and it then asks me where to save it. With a computer I can bring up whatever program I want to, with Apple it only shows me apps that I can use. I have saved it in every choice they've given me and tried to listen to it with each one, but have had no luck. Not one of them are music apps so I'm not sure what I'm doing wrong exactly. I have also tried it on my iPhone with the same results.
I have tried that, but it was never given the option to save to Dropbox before. I just tried to DL an audio file and it worked. It isn't a book I'm interested in though. I tried several books before and they didn't work. =/ Maybe it is just some files that work and others that don't? I will try a couple again. Thanks for the help.