My library offers audio e-books. I can listen to the .WMA file on my computer with no problems. However, I'm unable to listen to the file on my Treo 755P. According to my library, it should work fine on my Treo. Is there specific software or a setting that I'm missing?

Thanks in advance for your help!

I use PocketTunes to listen to books. My library provides Overdrive Media Console to deliver the files and transfer them to PocketTunes.