I wonder if the behavior you're seeing is (as was suggested earlier in the thread) that these are copy-protected CDs, designed to play on audio CD players but refusing to fully play on computer CD drives.
Nope. Not copy protected (I
did find one CD-ROM player that would read them) but instead just poorly mastered CDs,
I just finished ripping/encoding another audiobook tonight from a different publisher, and the disks were all 750+ MBs (74 minutes) and there were no problems whatsoever with them.
tanstaafl.