Non-XP systems will be using SAMBA as the connection technique for file/print sharing
(ie: ports 139,445 and lmhost v1 authentication)
XP (and Vista) have two authentication techniques
LMHASH and NTHASH
SAMBA access will require LMHOST V1 authentication
(it is possible to use V2 *if* all non-windows systems support V2)
Windows XP/Pro or Vista/Ultimate users who have set the Global Policy
Network security: Do not store LAN Manager hash value on next password change
located at
Computer Configuration, Windows Settings, Security Settings, Local Policies, Security Options
will not be able to use filesharing to non-windows systems.
The alternative tecnhnique is a regedit
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
click Add Key, type NoLMHash, and then press ENTER.
The GPO is preferrable, but XP/Home users must use this regedit to inhibit LMHASH
While it is true that setting this policy enhances the Windows security, it has a negative effect
on Sharing to non-Windows systems.
see the Microsoft KB article
http://support.microsoft.com/kb/299656
btw: this policy also stops LMHASH password cracking
so you choose Security and no sharing or Sharing and compromised security