For any one with a NEC/Renesas USB 3.0 Issue there are two solutions not yet available from Asus.
1) Update to current driver first here: http://downloadcenter.intel.com/Deta....1.19.0_PV.exe
2) Update Firmware from here: http://www.station-drivers.com/page/renesas.htm Download the Firmware Version 126.96.36.199.0.8 & 188.8.131.52.0.2 (Windows 32 & 64bits) dated 20/08/11 remove any devices conected to the 3.0 ports and for some reason needs to be run in compatibility mode win xp sp2. worked fine for me.
ASUS...... if you are listening why are we not being provided with these updated from our own manufacturer? Why do we need to go to a Intel site that is meant for there mother Boards? We are buying the most expensive boards out there aka Maximus IV Extreme Z and we deserve to have the latest drivers and firmware on a ASUS site not Intel or Gigabyte or Station Drivers.