Comment 10 for bug 1273925

Bug 243039 was linked to this bug. I can confirm what @jfhavet is saying that with usb-creator-gtk 0.2.56.1 which is the most recent version under Ubuntu 14.04, this issue persists. When clicking the "Erase" button the following error pops up :

org.freedesktop.DBus.Python.AttributeError: Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/dbus/service.py", line 707, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/usr/share/usb-creator/usb-creator-helper", line 218, in Format
    parent_dev = _get_parent_object(udisks, device)
  File "/usr/share/usb-creator/usb-creator-helper", line 49, in _get_parent_object
    parent = partition.get_cached_property('Table').get_string()
AttributeError: 'NoneType' object has no attribute 'get_cached_property'

I can also confirm that @jfhavet's workaround works well. Under English localized Ubuntu 14.04 the process is :

1 Open unity dash
2 Search for "Disks" or "udisksd" and launch "Disks"
3 Select your usb stick in the peripherals list
4 Click the little gears then select "Restore disk image..."
5 "Restore" Ubuntu iso image onto your stick