>So please do a "sudo umount /media/Data" and then re-run the command.

Well, there's nothing mounted to that directory, it's just dead/empty. As if it was unmounted but the directory remained. The partition is now mounted to Data__. So I'm not sure what exactly you mean...

Attempt to umount anyway:

$ sudo umount /media/Data
umount: /media/Data: not mounted


Attempt to mount to /media/Data via gnome-mount:

$ gnome-mount -vnbtd /dev/sde1 -m Data
gnome-mount 0.8
** (gnome-mount:6627): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2
** (gnome-mount:6627): DEBUG: read default option 'locale=' from gconf strlist key /system/storage/default_options/ntfs-3g/mount_options
** (gnome-mount:6627): DEBUG: read default option 'exec' from gconf strlist key /system/storage/default_options/ntfs-3g/mount_options
** (gnome-mount:6627): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2 with mount_point='Data', fstype='ntfs-3g', num_options=2
** (gnome-mount:6627): DEBUG:   option='locale=en_US.UTF-8'
** (gnome-mount:6627): DEBUG:   option='exec'
** Message: Mount failed for /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2
org.freedesktop.Hal.Device.Volume.AlreadyMounted : Device /dev/sde1 is already mounted.


Attempt to umount /media/Data__ and gnome-mount to Data:

$ sudo umount /media/Data__
$ gnome-mount -vnbtd /dev/sde1 -m Data
gnome-mount 0.8
** (gnome-mount:6644): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2
** (gnome-mount:6644): DEBUG: read default option 'locale=' from gconf strlist key /system/storage/default_options/ntfs-3g/mount_options
** (gnome-mount:6644): DEBUG: read default option 'exec' from gconf strlist key /system/storage/default_options/ntfs-3g/mount_options
** (gnome-mount:6644): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2 with mount_point='Data', fstype='ntfs-3g', num_options=2
** (gnome-mount:6644): DEBUG:   option='locale=en_US.UTF-8'
** (gnome-mount:6644): DEBUG:   option='exec'
** Message: Mount failed for /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2
org.freedesktop.Hal.Device.Volume.MountPointNotAvailable : The mount point '/media/Data' is already occupied

** Message: Given mount point name 'Data' is unavailable, trying with 'Data_'...
** (gnome-mount:6644): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2 with mount_point='Data_', fstype='ntfs-3g', num_options=2
** (gnome-mount:6644): DEBUG:   option='locale=en_US.UTF-8'
** (gnome-mount:6644): DEBUG:   option='exec'
** Message: Mount failed for /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2
org.freedesktop.Hal.Device.Volume.MountPointNotAvailable : The mount point '/media/Data_' is already occupied

** Message: Given mount point name 'Data_' is unavailable, trying with 'Data__'...
** (gnome-mount:6644): DEBUG: Mounting /org/freedesktop/Hal/devices/volume_uuid_F09C547A9C543CF2 with mount_point='Data__', fstype='ntfs-3g', num_options=2
** (gnome-mount:6644): DEBUG:   option='locale=en_US.UTF-8'
** (gnome-mount:6644): DEBUG:   option='exec'
Mounted /dev/sde1 at "/media/Data__"


Is this last one what you were after?