I ran into issues on my cube (stock Rage 128 and Radeon 7500) when trying to play DVDs after having installed OS 9 using the OS 9.1 disk (kept telling me that the hardware could not be found, which is weird knowing that it is an Apple-branded super drive and that it's working great in OS X 10.4). After reinstalling the OS using my OS 9.2.1 disk, the Apple DVD player software apparenly "registered the hardware" and DVDs play just fine. I'm not sure if it's related to the version of the Apple DVD software, DVD/video driver but using the 9.2.1 install did the trick for me. Not sure if it helps but I figured I'd at least throw my two cents out there

-- BeniD82