According to what system you are running different IOUSBFamily are needed. You can look it up here for a detailed decription of the problem and which files are needed:http://developer.apple.com/hardwaredrive...

or

just reinstall your system and the updates.

Debug releases of the IOUSBFamily kernel extension are used to provide information about USB device and interface detection, driver and interface matching, driver loading and information generated as a result of normal and abnormal conditions.

Unique debugging versions of the IOUSBFamily kernel extension are available for the different Mac OS X releases. It is important that you install the correct version of the IOUSBFamily kernel extension or you might find that the system will panic during startup or that your USB keyboard or mouse may not function properly.