Marc, Having had the same problem as you with the .aa files, I found a FREE work around. it requires a little more work, but can be done with any number of FREE file converters. Audible.com will allow you to burn the audio books to CD. Then it's simply a matter of ripping the CD's back to your hard drive in .MP3 format. Almost any of the free share ware file converters will convert CD format music to .mp3. Yeah it's an extra step, but other than the cost of some blank CD's it won't cost you a dime.