The end result is. A flash and restore will result in you putting an old smb.conf in place if there is a newer one.
What I was saying was that installing samba can touch /etc/samba, as it pulls in samba-common. Except that this is part of teh base image, so opkg knows it is already installed so doesn't bother to do it again.
Well, it is the package that would contain a new smb,conf file, so it is relevant.I've never heard of samba-common, I doubt anybody else has either, and from where I'm sitting it's not relevant.