Comment 4 for bug 995165

I have also seen this in 12.04 LTS AMD 64. In my failing environment, interface->dhcp is 1; interface->slaac is 1, and interface->dhcp6 is 0. The install syslog shows:

Network config complete
Writing informative header
Success!
Writing loopback interface
Success!
Writing DHCP stanza for eth0
Writing SLAAC stanza for eth0
Success!

/etc/network/interfaces shows as follows (sans some comments at top)

===== START =====
# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#NetworkManager#iface eth0 inet dhcp
# This is an autoconfigured IPv6 interface
iface eth0 inet6 auto
===== END =====

If I comment out the #NetworkManager# comment, then my network is fine - ifconfig shows IPv4 and IPv6 addresses, but the Network manager reports unmanaged.