[CentOS] Samba on Centos 5/6 differences

Kinda OT.

I've been trying to get Samba running on a Centos 5 box for some time 
now, but can't seem to get it to happen. I can not connect to the 
machine from our external network but I can connect from a box on the 
same network. So it seems like a firewall problem.

Funny thing is I have no problem with Samba on a Centos 6 box. For now, 
that's the one I'm using for all of my mounts. I have looked and looked 
at my firewall to try and find a difference in the "allows", but can 
find nothing, so I ask...

Does anyone have a clue as to whether there was a difference in the 
setup for Samba on Centos 5 from the setup on Centos 6 that might be a 
'gotcha'?

Sorry for the stupidity. I've checked all the ports needed, both TCP and 
UDP, and they all seem to be open. I'm hoping there was a change in 
defaults or something I'm just overlooking.

Thanks
steve campbell