You can use McShield as a second layer of protection against USB’s. This is install and forget
Download McShield to your desktop and install
It will initially run a scan and show the result as a toaster by the system clock
Then in the control centre select scanner and tick unhide items on flash drives
https://dl.dropbox.com/u/73555776/mcshield%20unhide.JPG
Plug in the drive and McShield will start a scan