Apparently my unit is an older one because it does not have the Apple 2.0 sticker. I contacted Audio Research about my problems and they said they would send me new PAL low level I/O drivers for my CD-9. I hope that fixes the problem.
These days Audio Research tech support leaves a lot to be desired. They won't take inquiries by phone. You have to do it by e-mail and then it takes up to a full week for them to respond.