permissions of a partition on USB stick not changing as root even

[Tapas Mishra]

I am having a USB disk.
I want to change the permissions of  folder on it from 700 to 755 (and
all subdirectories in it)
ls -l /media shows

total 26
drwxrwxrwx 2 tapas tapas  2048 2010-02-12 04:12 HPLAUNCHER
drwx------ 7 tapas tapas  4096 1970-01-01 05:30 vol1
drwx------ 1 tapas tapas 20480 2011-01-03 17:43 vol2



how ever even if I am trying following command as root

chmod -R 755 /media/vol2

permissions do not change.

This is the command I try always and after the cursor blinks for about
5-6 minutes I get the shell back.
What could be the problem?

Some outputs I am posting
lsusb shows
Bus 002 Device 002: ID 03f0:4507 Hewlett-Packard

fdisk -l shows
Disk /dev/sdb: 499.4 GB, 499405291520 bytes
255 heads, 63 sectors/track, 60715 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x579a78f1

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               2       59918   481283302+   f  W95 Ext'd (LBA)
/dev/sdb2           59919       60715     6401902+   c  W95 FAT32 (LBA)
/dev/sdb5               2       59918   481283271    7  HPFS/NTFS


-- 

Output from /var/log/syslog  is

Jan  6 10:24:12 tapas ntfs-3g[2278]: Version 2010.3.6 external FUSE 28
Jan  6 10:24:12 tapas ntfs-3g[2278]: Mounted /dev/sdb5 (Read-Write,
label "vol2", NTFS 3.1)
Jan  6 10:24:12 tapas ntfs-3g[2278]: Cmdline options:
rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,dmask=0077
Jan  6 10:24:12 tapas ntfs-3g[2278]: Mount options:
rw,nosuid,nodev,uhelper=udisks,silent,allow_other,nonempty,relatime,fsname=/dev/sdb5,blkdev,blksize=4096,default_permissions
Jan  6 10:24:12 tapas ntfs-3g[2278]: Global ownership and permissions
enforced, configuration type 1