I think lombards needed the PCMCIA DVD card while the Pismos didn't for viewing DVDs.

Are you running OS 9.2.x? It looks for specific hardware decoder cards on specific machines to play back DVDs. On my B&W with a G4 it would play back DVDs using the ATI rage 128 with DVD decoder card using OS 9.2.2 but not when I have a Radeon video card (which should be able to do hardware decoding but the OS doesn't know that without patches/hacks). I believe OSX does not recognize the older hardware cards (B&W G3 or Wallstreet/Lombard).