I had the same problem using UNetBootin to create the USB device. I thought that I could tell it not to edit the bootloader and then I would edit it later using a separate install of Ubuntu however the problem persisted.
The problem appears to be with the installer it self. I opened up a terminal to try to manually force unmount the /cdrom mount point it failed even when done as root. It continued to insist that the partition was in use and could not be unmounted. -- usb startup disk failed to unmount /cdrom when change partition tables https://bugs.launchpad.net/bugs/292493 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
