Not positive here, but it looks like the entry for your system in /etc/hosts is mucked up - I believe it should match exactly /etc/hostname. For instance, my /etc/hostname (my system is named osaka):
and my /etc/hosts:
I would try to change the second line in /etc/hosts to be just "dell" instead of what it is now. Perhaps something got tripped on the upgrade.
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback