files copied via nfs mount are unreadable on windows

Hello,

Forgive me for possible posting this, i think this was discussed a few years ago, but i cant for the life of me find it.

we are getting a problem where files copied via an nfs mount point on linux are un readable on windows by the same user.

in a nut shell the problem looks like this:

When our render user on linux , creates a file directly on the nfs mount it is readable by the windows render user.

When our render user on linux creates a file directly on the nfs mount, then copies / renames the file on the nfs mount , the windows user cannot read the file anymore.

simplist linux test to recreate the problem:

create a file with the command: 'touch test.txt'
    - this file will have the correct permissions on it.

copy the file with the command: 'cp testfile.txt teste_copy.txt'
    - the copy file have BAD permissions on it.

Can some one point me in the right direction please?

Cheers

Kym