I have the same issue. So I usually invoke it with below command as a workaround
usb-creator-gtk -i my.iso -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/978691 Title: usb-creator ignores selected source disk image To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/usb-creator/+bug/978691/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
