I don't believe that Apple wants to fix this problem because it's in their interest to try to direct traffic to their itunes site where you can choose an audiobook. music or movie that you pay for. The newest Apples imacs which now about a year old do not have a cd or dvd slot --so that you can't use your disks.You have to plug in a peripheral unit like we did back 15 years ago. It a total pain especially since Apple always puts their ports in back. So the ultra slim high style Apple has a series of USB cords hanging out the front of the computer so I quickly connect my camera, hard drives, scanners, printer- it's so elegant.
I didn't find that Petter's solution worked for me.(PS- in Mountain Lion, your library file is invisible- you have to click on "go" while holding down the option key to see your library file). They think we are all idiots and will throw out the wrong files, so they hid the library file. Ha ha-- that's really funny Apple! Took me hours on the internet to find tout how to find the library file.
What I finally did to fix the playing order on audiobooks was to click "get info" (command I) on every track file and manually put in the disk information.(1 of 12 disk, 2 of 12 disk). It takes forever and is very confusing particularly if it's a long book and you have 20 some disks. I remember doing this years and years ago on the old computers from around 2000.
The idea that Apple can't fix this is ridiculous. The audiobooks copied just fine on the 2009 imacs and played in perfect order. They don't want you to be able to play your older media on these computers. I don't believe cds and DVDs are really obsolete- there's still a lot of them being sold. Apple is trying to make them obsolete. And if you don't want to fall in with their new profitabilty system, then they figure you can go out and download some 3rd party script or resort to maually renaming everything. I really resent that they waste my time over some minor issue like this, that they could easily fix.
This Apple imac from late 2012 is the last Apple I will buy. I don't think Steve Jobs would have done this to customers because he was always tuned in to what customers wanted even before customers knew what they wanted. This new thinking at Apple is all about what makes Apple profitable- not what is convenient for users. They don't care that it is easier to just pop a music CD than to ditz with all their I-tune playlists complex crap and peripherals to clutter up your desk. Apple thinks of themselves as cutting edge, but really the new Apples are 2 steps backwards.