Hi
you may also want to make sure that you have allowed the ports on your firewall. I had the same issue and this fixed it :
open up these ports to your subnet so that the connection requests from the XP boxes make it to the server.
On FC2 System Settings -> Security Level, in “other ports” add the string: “137:udp, 138:udp, 139:tcp, 445:tcp” . Click OK.
On FC4 System Settings -> Security Level ->SELinux -> Modify SELinux Policy ->Samba then allow samba (note i selected one at a time and retested it)
then restart your smb service either by GUI or /etc/rc.d/init.d/smb restart
i hope this helps you...
Jitesh allways yahoo me.
