<snip> # General config files insinto /etc/samba doins "${CONFDIR}"/{smbusers,lmhosts} newins "${CONFDIR}/smb.conf.example-samba3" smb.conf.example newpamd "${CONFDIR}/samba.pam" samba use winbind && doins ${CONFDIR}/system-auth-winbind </snip> Well, this goes to /etc/samba/system-auth-winbind and PAM doesn't look there for sure. (BTW, the full /lib/security/ path is unneeded in the config, and can be broken on amd64 if you are missing the symlinks).
fixed in version bump. Thanks.