Actually, since my last message (#161) I have found that, very, very occasionally, an invalid second eth0 connection is created even in the following situation:
IPv6 enabled in aliases.conf: yes
IPv6 enabled in avahi-daemon.conf: no
[ipv6] method=ignore
[ipv4] method=auto
[ipv4] may-fail=false
So it seems the only sure-fire way of stopping NetworkManager from
creating an invalid second eth0 connection (IPv6 Link-Local connection) is to
disable IPv6
system-wide.
