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