This has put my Mbox back in business, at least as a holdover until Digidesign issues its own updates. But please note that, just as with Digidesign's Core Audio driver under Panther, some apps will fail to launch unless you temporarily remove the plugin from /Library/Audio/Plug-Ins/HAL. In fact, I just discovered that Dashboard widgets don't work unless I do that. And ditto for VueScan.