sudo umount hangs when booting with systemd

[Zenaan Harkness <zen@freedbms.net>]

I have a directory /media/USB01

Nothing is mounted on this directory.

When I run the following, after booting up with systemd, the command hangs:
sudo umount /media/USB01

A Ctrl-C breaks the hang.

$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda5 during installation
UUID=e73a71d3-a391-40bc-9d45-55fa72f245c1 / ext4
errors=remount-ro,nodiratime,noatime,user_xattr,journal_async_commit,min_batch_time=1000
0 1
# /boot was on /dev/sda3 during installation
UUID=75e1d222-c9df-4d10-93de-9da4cf005158 /boot ext2 defaults 0 2
# swap was on /dev/sda6 during installation
UUID=25d4ff20-1c78-4e1d-bd2a-2a0060e85f9a none  swap sw

# The following is done by /etc/default/rcS "RAMTMP=yes" option
#tmpfs /tmp tmpfs defaults,nodiratime,noatime,mode=1777

#/zenlocal/zen/justa /home/justa none bind,comment=systemd.automount
/zenlocal/zen/justa /home/justa none bind
/zenlocal/zen/  /home/justa/zen none bind

UUID=9E18AD0C18ACE50D /media/c ntfs-3g defaults,uid=1000,gid=1000,noauto

UUID=3EE6330B1FADCDD2 /media/SNAP000001 ntfs-3g
defaults,uid=1000,gid=1000,posixovl,nodiratime,noatime,comment=systemd.automount
UUID=6fce0b79-b658-4072-af58-376a5630c190 /media/z55 ext3
user,nodiratime,noatime,comment=systemd.automount

/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto
/dev/sdb1       /media/usb0     auto
rw,user,noauto,nodiratime,noatime  0       0
/dev/sdb2       /media/usb1     auto
rw,user,noauto,nodiratime,noatime  0       0
/dev/sdb3       /media/usb2     auto
rw,user,noauto,nodiratime,noatime  0       0
/dev/sdb4       /media/usb3     auto
rw,user,noauto,nodiratime,noatime  0       0
/dev/sdb5       /media/usb4     auto
rw,user,noauto,nodiratime,noatime  0       0


Perhaps these two lines above are causing a problem for systemd's auto- stuff?:
/zenlocal/zen/justa /home/justa none bind
/zenlocal/zen/  /home/justa/zen none bind

Also, ls /media/ works, but ls -l /media/ similarly hangs! Again,
Ctrl-C aborts the hung command.

Any ideas?
Zenaan