I have an Acard AEC-6280M IDE card. It was originally installed when I only ran OS 9 (way back in 2000) and worked perfectly. When I installed OS X, it continued to work perfectly until recently. Now, it shows up and it works okay when I boot in X, but when I boot in 9, it (and the attached drives) don't show up.
Under 9, the card shows up in the Apple System Profiler, but Hard Disk Toolkit doesn't see it, and Drive Setup doesn't see it. The drives don't show up in any place under 9.
I installed one of the drives on the Acard under X, and made sure I checked the "Install Mac OS 9 drivers". I don't think that would have anything to do with this though, this seems like a driver or firmware problem.
I know this card is advertised as driverless, but I seem to remember some acard file in my extension folder way back when I ran in 9 all the time.