Is this partition in your /etc/fstab? If so, you cannot unmount it as normal user.
If it is not in your fstab, please copy&paste the output of
gnome-umount -vbd /dev/sdb2
and do
lshal > /tmp/hal.txt
and attach /tmp/hal.txt here.
Is this partition in your /etc/fstab? If so, you cannot unmount it as normal user.
If it is not in your fstab, please copy&paste the output of
gnome-umount -vbd /dev/sdb2
and do
lshal > /tmp/hal.txt
and attach /tmp/hal.txt here.