Why would an Audio Interface PCI card work in one Mac G4, but not in a newer, similar computer? My Sonorus STUDI/O audio interface card has been working great in my G4 450 (AGP), through various MacOS versions, now in OS 9.2.2, using LOGIC Pro 6. Putting the card in a Power Mac G4 Dual 1.25 Ghz (MDD Mirror Drive Door), the card is recognized by Apple System Profiler, but Logic abruptly quits without explanation as soon as it starts up and tries to acknowledge and integrate the card. Throwing away Logicâ€™s Preferences will let me successfully start up LOGIC, and choosing the basic MacAV as the audio engine will work just fine (so itâ€™s not the application itself thatâ€™s broken). But if I specify the STUDI/O, as soon as I relaunch LOGIC to activate that choice, the program just quits without explanation again. Same system (OS 9.2.2) as in the G4 450 (except that the Mirror Driveâ€™s OS 9 was a slightly newer, machine-specific build). No special drivers needed, as LOGIC supports the card directly. I tried all available PCI slots, with no difference. So why would a PCI card suddenly not work at all in a newer, but comparable Mac? Any ideas? Thanks, Peter * * * * * Additional bit: The STUDI/O card is not supported in OS X, and Sonorus has closed its doors. So there's no help forthcoming from that direction. But in OS 9, everything should be good to go. Could a somewhat newer, faster computer like the Dual 1.25 really have that much of a detrimental impact on a PCI card?