OS X can´t read PhotoCDs

Hmm. I can successfully read multi-session CD's with many many sessions.

OTOH, when I upgraded to 10.0.1 I couldn't read any CD's, but when I reinstalled 10.0 and then upgraded again, it worked again. Weird.

but PhotoCDs are still not usable. I´m working on an iMacDV Indigo (Model 2000). I don´t know the difference between the ISO-Format and the PhotoCD-Format but I think it has to be the same, so I don´t understand, what´s the problem.
I can read PhotoCD and PeCe Cd's on my G4/500/DP
with 10.0.1 and firmware 4.18f5

I only have one PhotoCD to test though, "An Introduction to Photo CD" by Philips 1992.
I use PhotoCDs in System 9.1 on another Partition and it works fine. They are not available in MacOS X or the Classic 9.1 which are together at one Partition.I tryed to use the SystemExtension "Joliet Volume Access" (www.tempel.org ) in Classic, but it doesn´t work.But I can see the 9660 Files like .exe and these things, if I put a ISO-CD in my Drive in MacOS X.It only doesn´t work with PhotoCDs.