This is an interesting situation I have going on. I have a PowerMac G4 Quicksilver model that I just got my hands on. There is only 2 native USB ports in the rear, so i added a USB 2.0 pci card to it. I have a wireless mouse and keyboard receiver plugged into the PCI card and that works great. When I plug a USB flash drive into one of the 2 native ports, its finds it and comes right up. If I plug it into any one of the 4 new USB ports off of the PCI card, the computer wont see it. The LED on the flash drive lights up so I know it gets power, and the mouse and keyboard work off it too. Any thoughts?