I'm quite sure this is the same bug as Bug #36252 and Bug #111541. It should be a EJECT command problem (both launched in terminal and via Nautilus) UMOUNT command works fine.
Check out my comments on Bug #36252 https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/36252/comments/26 and Bug #111541 https://bugs.launchpad.net/ubuntu/+source/eject/+bug/111541/comments/12 -- nautilus, media containing multiple partitions cannot be unmounted (USB connected) https://bugs.launchpad.net/bugs/108643 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs