Permission problem

[James Ng Yuen Sum <james_nghk_debian_user@yahoo.com.hk>]

Hi,
After I have upgraded from woody to sid (seem i run "apt-get upgrade
gcc"), the "chmod" command cannot work normally.
When i am in woody, after i edit the file /etc/fstab, and remove the
read-only property in my two files, which are used in Windows XP system.
That is the two files, /mnt/drive_c /mnt/drive_d contain the files in
Windows XP system. When i am in woody, i can use "chmod" command to
change the files which can run in user. But when i upgrade to sid, even
using "chmod" command cannot change the file in /mnt/drive_c and
/mnt/drive_d to be used in user.

So, i want to ask how can i change so that the user can use the files
/mnt/drive_c and /mnt/drive_d (root is the owner of these two files from
ls -l)

Regards,
James Ng