Comment 30 for bug 345221

This is what is needed to make samba with browsing work:

On the server (assumes Intrepid server):
$ sudo ufw allow Samba
$ sudo ufw logging on
$ sudo ufw enable
$ sudo ufw status
Status: loaded

To Action From
-- ------ ----
Samba ALLOW Anywhere

Then on the client:
$ sudo ufw allow from any port 137 proto udp
$ sudo ufw logging on
$ sudo ufw enable
$ sudo ufw status
Firewall loaded

To Action From
-- ------ ----
Anywhere ALLOW 137:udp

The client rule is needed because when browsing, the client sends out a broadcast packet and the servers respond from their own ip address. The broadcast packets and server addresses are different so they aren't added to the connection tracking table, so a specific rule is needed. You can of course limit this to your internal network like so:
$ sudo ufw allow from 192.168.0.1/24 port 137 proto udp

I tested this configuration and confirmed it works fine via Places/Network. If you are stilll having problems, please ensure that you enabled logging as above, and please give the UFW entries from /var/log/kern.log.