I think this is a ML issue as it's only started since the upgrade after 6 months plain sailing. I have these 2-Port USB Cable KVM Switch Keyboard/mouse USB switchers for my Mac/PC setup (I'm using a 2008 Mac Pro). Since the upgrade I'll be using the PC and try to switch back to the Mac. When I switch back the Mac won't send power to the mouse. If I directly connect it I get the same problem. To resolve I have to reboot. Anyone get something similar with USB under ML?