We've seen some reports of AX88772 based adaptors being recognized on Leopard without needing to install any drivers. The system.log reports the device is being matched by AppleUSBEthernet. We've also had some problem reports of not getting a DHCP Lease. If you're experiencing difficulty, please check the system.log to see which driver is actually being used. With the announcement of the MacBook Air, Apple began shipping their own USB-to-Ethernet adaptor which AppleUSBEthernet is designed to support. I understand Apple's USB-to-Ethernet adaptor should work on other Macs running Leopard 10.5.2 or later (Daniel Sumorok has verified this). It can also be used on systems running Mac OS X 10.3.9 or later by installing our latest USBAx8817x driver. Apple's driver is not designed to support 3rd party USB-to-Ethernet adaptors or prevoius OS versions. We have modified our own driver to take precedence over Apple's driver when it is installed, and recognize the Apple USB Ethernet Adaptor.