Dear Norlan,
I'm experiencing a similar problem and my USB, although connected and appearing the the System Status > USB Details , does not show total capacity and file format in the Disk Management > Drive Properties or Disk Management > USB Settings. Hence, when I go to Shared Folders, the usbdisk1 does not appear and I am unable to share/access it.
I have another functioning USB disk and have both of them formatted in Ext3 format. I've tried the unassignment multiple times to no success... how exactly did you manage to solve this?
thanks in advance,
Diogo