You didn't say what software you are using to rip the tracks and what software you use to encode the tracks. But it sounds that the encoding process is what is crashing, so it might be a fault in the encoding software. But a crash of the whole system is a symptom of a big problem.
Are the audio books were real CDs (with a compact disk digital audio label on them), who manufactured them and did they include some sort of label claiming they have copy protection?
No, the CDs don't have the official label on them nor is there any claim of copy protection.
The obvious thing to do is to first rip and then encode manually (with the same software that you were using already) as ITL suggested.
Suggestions for the codec:
MP3 is inferior in quality to all other modern codecs these days. Why do you insist so much on it? Even WMA is better. My personal choice is Ogg Vorbis, because it's free, but if it's unsupported on your devices, AAC ("MP4") is also a decent choice. (Or even Speex in your case.) And of course, hard disk space is cheap, so you might just use FLAC which beats all. But the point is, if you can't fix your problem, switching to a different codec might be actually a good thing.
As I said, I did rip them to WMA successfully, then converted to MP3 afterward with no problem.
As for why I want MP3, it's because I'm putting it on an iPod as an audio book. To make that conversion, you can either:
1. Use a program I found that converts MP3s straight to the iPod audio book format, combining all the MP3s files into one file in the process. This program only accepts MP3 as an input.
2. Import whatever other file type into iTunes and convert to .m4a, then combine all those .m4a files into one (I forget which program, but there's something out there to do it), and finally change the extension to .m4b and reimport into iTunes. Alternatively, the files can be combined before conversion in iTunes, but either way, there are a lot more steps in this process.
Suggestion for the crash:
If your system crashes like that, there is something wrong with it. Inspect your RAM with software like memtest86, check that high CPU load doesn't cause your system to crash by a CPU stress test tool. Running other kinds of encoders (as suggested above) might also reveal more.
Use different CD rippers, different encoders, try encoding and ripping at the same time and separately, and it will reveal what triggers the crash. If you “fix it” don't think that just because “it works” it is fine. If you have a hardware problem your system might be silently corrupting your data as we speak.
And, of course: I'm paranoid, so the first thing that came to mind is that you might have some malware designed to hinder CD ripping. That's a bit crazy, but you might examine your system carefully to make sure you don't have anything like that.
As I said, I used two different ripping programs. Both of which rip and convert on the fly. The two programs were CDEx and Windows Media Player. Both programs could rip the CDs and encode to something other than MP3 successfully. I tried the same thing on two different computers (both programs on both computers) with identical results, so I don't think it's a hardware fault or malware issue.
I had already checked all that out, and completed the task, I was just wondering if it is possible to put something in the data stream to make the conversion process crash.
