Creating VirtualBox USB rawdisks in Ubuntu

I recently was playing with a new 4GB usb stick and I wanted it install a rawdisk VirtualBox VM on it.  This would give a portable VM with decent speed.When I was trying to create the raw disk formated disk with the following command:

#> vboxmanage internalcommands -rawdisk /dev/sdc -filename ~/VirtualBox\ VMs/usbstick.vmdk 

I recieved the following error.  I even got this error running as root.  I determined it wasn't a permissons issue.

VBoxManage: error: Cannot open the raw disk '/dev/sdc': VERR_MEDIA_NOT_PRESENT
VBoxManage: error: The raw disk vmdk file was not created

After verifying that the device file did truely exist and that the permissions were not an issue.  I did some wondering.  What else would be touching this.  Then I noticed gnome (nautilus) was automounting USB sticks.  I then disabled the usb stick automounting.  This affects all USB mass storage devices.  I did this by opening the gconf-editor program.

#> gconf-editor

I then browsed thought the menu tree to apps -> nautilus -> preferences localtion.  Then in right column I disabled the media_automount and media_automount_open options.  Close gconf-editor.  Unplug and reinsert the usb stick. Now I was able to create the rawdisk without a problem. 

#> vboxmanage internalcommands -rawdisk /dev/sdc -filename ~/VirtualBox\ VMs/usbstick.vmdk 
RAW host disk access VMDK file /home/hydrian/VirtualBox VMs/usbstick.vmdk created successfully.

It seemed that nautilus was grabbing and holding control of the USB stick even after I unmounted it.   After disabling the above options, nautilus now never grabs access unless told to.