Share files over LAN to Windows 7 clients?

I am looking for info on setting up File Sharing in SLS to allow a user on our LAN to access share points from Windows 7 via Bootcamp. Currently the user can access the share points from the Mac environment, but using the same credentials from W7 fails to connect.

Here is more info:

1. We will assume there are two users on the server. Both are local accounts, not Open Directory. Both users are members of the group All Users, and there are identical user accounts with the same passwords in W7:
   1. Admin (can administer server)
   2. User1 (cannot administer server)
2. There is a share point (we'll call it Share1) that is set to Allow Full Control to the All Users group, and it is visible from Windows 7 when choosing "Browse..." when mapping a network drive using User1's login credentials.
3. There is another share point (Share2) that has the following permissions set in Server Admin, in this order:
   1. User1 - Allow Full Control
   2. All Users - Deny Read
4. Share1 is visible in W7 from either account. I am assuming that because 3.1 above is listed above 3.2 in the permissions hierarchy for Share2, it takes precedence. At least it has worked this way when accessing the share point from the Mac environment. I don't want to change this if it will risk allowing access to other members of the All Users group.
5. Share2 is not visible when logged into W7 as User1, but it is when logged in as Admin.

Hopefully there's a simple answer to this. Thanks in advance for any helpful tips.