From the Recorded Books folks:
"NetLibrary and Recorded Books recently replaced over 165 eAudiobook titles with iPod-compatible versions. With this exciting update, the file format of the titles was changed from the WMA (DRM-protected) format to the MP3 (DRM-free) file format."
We're still working on getting MARC records in the right format to share with all of you; if you have downloaded records on your own for Recorded Books, you'll need to change the records on your own (and share your records with us!).