Server 2008 File access for non-domain computers

Hi
I have a number of shares configured on our office server which were
accessible to specific users. Because a number of our computers are not
ye in the domain, these users had to provide login credentials when
accessing these shares. When a user on a non-domain machine now trys to
access a share he immediately gets a "access denied" message which is
diagnosed as "this user doesnt have the correct rights". He isnt being
asked for any login credentials.

I have checked the NTFS and share permissions and these are all set
correctly. Is there a policy option that prevent non-authenitcated users
being asked for login credentials when accessing shares or is there
anything else I can check to try and resolve this?

Roger.