Greyed USB drives on Virtual box Guests

   I use virtual box   on my Ubuntu  9.10 box to  run windows XP. ( I use it for some EDA tools like Proteus ). This morning Virtual Box prompted me  to upgrade to version. 3.1.4 and I upgraded it . When I tried to put my Usb Flash drive in the guest OS , the drive was shown grayed as in the screen shot below.

 

 I searched the net for a solution and finally did the following steps to fix it.

Click on System-> Administration->Users and Groups 

Click on the Key button near"click to manage "


Click on Manage  groups and select vbx users from the box


Click on properites and  tick  your username.

   .

Now restart the computer. Next time when you start the machine your flash drives will be visisble..