I've tried various different versions with an old external CD drive (that's in the supported devices list) but at best it will only mount a CD the first time it's installed. After a reboot it will never mount a disc again even though the driver is loaded and everything appears to be working. The Finder stops responding and I have to reset the Mac.
The freeware CD Sunrise driver works fine but I'd like audio support and perhaps hybrid discs too (anything other than a plain HFS disc is unreadable with it).
I'm doing most of my "testing" on my LC III which has 7.1, 7.5.3 and 8.1 installed. I'm mostly using 7.1 for this but have tried 7.5.3 too with no joy.
Update:
I've noticed that if I have the disc in the drive during startup it will mount. But it doesn't like mounting discs inserted when the system is running.