Got a fright at the weekend, after my PC booted to the login screen sans problem I found I couldn't login. Not because my password/user had become corrupt or anything like that but I simply could not enter my username/password as both my mouse and keyboard were dead.
Both are plugged in to the box via USB->PC2 adaptors. I unplugged them and plugged into my USB hub and presto - fully functional peripherals again. :/
So it seems the last update either broke the way the OS talks to PC sockets or Fedora guys have switched off support by default. Took me by suprise that sort of change would be done in an update rather than a major release as it seems a shift in policy (assuming it was switched off rather than broken).