VirtualBox doesn't recognize USB [duplicate]

Possible Duplicate:
Set up USB for Virtualbox

I have Ubuntu 12.04 as host and Win7 as guest. I installed VirtualBox 4.1 and Extension Pack 4.1 from Oracle website. I also enabled USB 2.0 from Settings of my VM. My Win7 VM doesn't regconize USB (Flash Drive and Kindle Fire). How to fix it?

Update: I added my current user to vbusers group but it doesn't work as well.

I had the same problem and fixed it by clicking in the VirtualBox group of my user. You can access it installing gnome-system-tools (it does not come with Ubuntu 12.04 Precise Pangolin), either via the Ubuntu Software Center, Synaptic or by typing in the terminal:

sudo apt-get install gnome-system-tools

Remember that to paste in the terminal you have to use CTRL+SHIFT+V, as opposed to CTRL+V

You will probably have to enter your password to allow the installation and add a Y (as in yes) to finish installing the packages.

Then you head to your Dash home and type users. You will see two applications. The good one is Users and Groups.

You then have to click on Advanced settings for your user and enter your password.

Now you will be shown a window with three tabs. Click on User Privileges. Find the line that says Use Virtualbox virtualization solution and then OK.

You may be asked to enter your password again. Then click on Close and log-out and log-in again.

When you start VirtualBox you should see a whole bunch of new USB devices.

Good luck!

Dont forget to add you as a vboxusers user. You have to be in the vboxusers group.

sudo adduser $USER vboxusers

To verify it:

$ groups
yourUserName : yourUserName adm cdrom sudo dip plugdev lpadmin scanner sambashare vboxusers

If this still doesn't work, Log out and log back in.