Comment 3 for bug 838388

From the USBCreatorLog files:

usb-creator 2011-08-31 22:47:54,627 (DEBUG) install.py:309: create_persistence
usb-creator 2011-08-31 22:47:54,635 (DEBUG) misc.py:129: ['dd', 'if=/dev/zero', 'bs=1M', 'of=/media/D320-9BE6/casper-rw', 'count=1024']
usb-creator 2011-08-31 22:49:28,302 (DEBUG) misc.py:129: ['mkfs.ext3', '-F', '/media/D320-9BE6/casper-rw']
usb-creator 2011-08-31 22:49:29,481 (ERROR) install.py:147: Exception raised:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/usbcreator/install.py", line 143, in run
    self.install()
  File "/usr/lib/python2.7/dist-packages/usbcreator/install.py", line 583, in install
    self.create_persistence()
  File "/usr/lib/python2.7/dist-packages/usbcreator/install.py", line 330, in create_persistence
    popen(mkfs_cmd)
  File "/usr/lib/python2.7/dist-packages/usbcreator/misc.py", line 139, in popen
    startupinfo=startupinfo)
  File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1239, in _execute_child
    raise child_exception
OSError: [Errno 2] File o directory non esistente