samba - Sep 2012 - windows 7 problems

We are having problems with some windows 7 machines hanging when they access
folders with in a share. We sell new pc's and laptops and use the samba
server too hold software such as antivirus etc.
I have googled the problem and there seems a few registry and security policy
tweaks for windows 7 but it is not practical for us too tweak new machines like
that before they go out.
Is there any thing that can done on the samba end ?

samba36-3.6.5       A free SMB and CIFS client and server for UNIX
FreeBSD  8.0-RELEASE

[global]
        netbios name=nas
        workgroup=workgroup
        security=share
        encrypt passwords=yes


# Debug logging information
        log level = 2
        log file = /var/log/samba/samba.log.%m
        max log size = 50
        debug timestamp = yes


[Utilities]
        path=/usr/server-shares/nas
        readonly=no
        guest ok=yes
        force group = samba
        force user = samba
        create mask = 770
        force create mode = 770
        security mask = 000
        force security mode = 770#

        force directory mode = 770
        directory mask = 770
        directory security mask = 000
        force directory security mode = 770

Log sample
[2012/09/27 09:51:49.887729,  2] smbd/sesssetup.c:1279(setup_new_vc_session)
  setup_new_vc_session: New VC == 0, if NT4.x compatible we would close all old
resources.
[2012/09/27 09:51:50.989047,  2] auth/auth.c:319(check_ntlm_password)
  check_ntlm_password:  Authentication for user [nobody] -> [nobody] FAILED
with error NT_STATUS_NO_SUCH_USER
[2012/09/27 09:51:50.989217,  2] auth/auth.c:319(check_ntlm_password)
  check_ntlm_password:  Authentication for user [nobody] -> [nobody] FAILED
with error NT_STATUS_NO_SUCH_USER
[2012/09/27 09:51:50.989297,  2] auth/auth.c:319(check_ntlm_password)

Thanks 
Terry