This seems to be a problem that's been kicked around apple's support page forums a lot, but I still can't seem to fix it -- I upgraded to 9.0.4 on my G4/400 PCI and now I can't play DVDs. I get the message that the appropriate hardware isn't there. To pre-empt the non-solutions I've already tried, it doesn't help to reinstall Apple DVD player 1.3 or 1.2 clean -- neither of which should have problems the way 2.2 does because it's designed for the software DVD decoding of iMac DVs and AGP G4s. I've tried changing my monitor resolution all across the board to see if that helped - no luck. I get a similar error message from both v 1.2 and 1.3. I don't know if the problem is the player (3rd party software replacement might fix) or the driver. Any help would be great.