I have samba services running on opensuse 12.1 64 bit. It was given a netbios name, firewall port open and set up as part of a work group, not a domain server. Also in my lan is windows xp. I set xp workgroup name to workgroup and both opensuse and xp see each other in windows explorer and dolphin. On the xp side, when I click on the network shared folder called Downloads in opensuse, a dialog pops up for user name and password. I enter both user and password and the dialog box pops back with 'OPENSUSE12.1\myusername' and password. I do not know why my credentials are refused. On the opensuse side, under network, samba shares, workgroup, I see both computers. I click the xp icon and 'could not connect to host'. I can not figure out what I need to do for both to accept the connection. I would prefer no credentials, but could live with entering them for security reasons.

may be your iptables service is running so stop the iptable service and check from both side ip of your xp machine and ip of your linux machine pinging each other.

After I made the post, I remembered to set up file sharing on the xp box. I was then able to browse the xp box from the linux box with no problem. I remember having a similar permissions problem with filezilla that I solved. The firewall is set for those samba and netbios ports to be open, so the linux box is probably locked down,