[Virtualbox] USB problem with Virtualbox 1.6.6

# nano /etc/fstab

modify the line for usbfs like this

usbfs /proc/bus/usb usbfs auto,busgid=XXX,busmode=0775,devgid=XXX,devmode=0664 0 0

where XXX can be dicovered by

$ grep vboxusers /etc/group

and then

# mount usbfs

finally add the mount

# echo "mount usbfs" >> /etc/init.d/boot.local

ref. http://linux.knightnet.org.uk/