Why are all files listed as read-only?

[shapi003 at mc.duke.edu]

user:     stuff
group: stuff

chmod 575 *              (i.e., rx rwx   rx)

/etc/group
     stuff::puffin

In NT if you map drive (net use * \\server\stuff /user:puffin password ) and
then right click on any file on mapped drive and look in properties, the files
are set are read only.  Why is the read-only attribute on?

If I do an ls -la on nt on mapped drive to unix system it shows all files with
read-only      r r r