Having the same issues. Using an Apple USB charger (no problems with quality there!) and just trying to run a wired keyboard and mouse straight from the usb sockets. Have tried powered USB hub as well but no joy
Command line is great. Keyboard works and mouse has the light on underneath it. But upon going into xwindows (or whatever it is, haven't had chance to find out!) the mouse conks out.
Keyboard and mouse are basic Genius models.