It looks like we're not capturing all the logging we want to, because rsyslog starts to late - it doesn't start until the filesystem is fully available, whereas portmap starts as soon as local filesystems and localhost are available.

You could try editing these lines in /etc/init/portmap.conf:

  start on (local-filesystems
          and net-device-up IFACE=lo)

to this:

  start on (local-filesystems
          and net-device-up IFACE=lo
          and started rsyslog)

This way, portmap doesn't try to start before logging is going.

From the log you have, though, this is interesting:

Oct 26 23:30:59 htpc init: event_pending_handle_jobs: New instance gdm
Oct 26 23:30:59 htpc init: gdm goal changed from stop to start
Oct 26 23:30:59 htpc init: gdm state changed from waiting to starting
Oct 26 23:30:59 htpc init: event_new: Pending starting event
Oct 26 23:30:59 htpc init: udevmonitor goal changed from start to stop
Oct 26 23:30:59 htpc init: udevmonitor state changed from running to pre-stop
Oct 26 23:30:59 htpc init: udevmonitor state changed from pre-stop to stopping
Oct 26 23:30:59 htpc init: event_new: Pending stopping event
Oct 26 23:30:59 htpc init: job_register: Registered instance /com/ubuntu/Upstart/jobs/networking/_
Oct 26 23:30:59 htpc init: job_register: Registered instance /com/ubuntu/Upstart/jobs/networking/_
Oct 26 23:30:59 htpc init: job_register: Registered instance /com/ubuntu/Upstart/jobs/networking/_
Oct 26 23:30:59 htpc init: event_pending_handle_jobs: New instance networking
Oct 26 23:30:59 htpc init: networking goal changed from stop to start
Oct 26 23:30:59 htpc init: networking state changed from waiting to starting
Oct 26 23:30:59 htpc init: event_new: Pending starting event
Oct 26 23:30:59 htpc init: Handling starting event
Oct 26 23:30:59 htpc init: event_finished: Finished starting event
Oct 26 23:30:59 htpc init: gdm state changed from starting to pre-start
Oct 26 23:30:59 htpc init: gdm state changed from pre-start to spawned
Oct 26 23:30:59 htpc init: gdm main process (1011)
Oct 26 23:30:59 htpc init: gdm state changed from spawned to post-start
Oct 26 23:30:59 htpc init: event_new: Pending started event
Oct 26 23:30:59 htpc init: Handling stopping event
Oct 26 23:30:59 htpc init: event_finished: Finished stopping event
Oct 26 23:30:59 htpc init: udevmonitor state changed from stopping to killed
Oct 26 23:30:59 htpc init: Sending TERM signal to udevmonitor main process (446)
Oct 26 23:30:59 htpc init: Handling starting event
Oct 26 23:30:59 htpc init: event_finished: Finished starting event
Oct 26 23:30:59 htpc init: networking state changed from starting to pre-start
Oct 26 23:30:59 htpc init: networking state changed from pre-start to spawned
Oct 26 23:30:59 htpc init: networking main process (1017)
Oct 26 23:30:59 htpc init: networking state changed from spawned to post-start
Oct 26 23:30:59 htpc init: networking state changed from post-start to running
Oct 26 23:30:59 htpc init: event_new: Pending started event
Oct 26 23:30:59 htpc init: Handling started event
Oct 26 23:30:59 htpc init: event_finished: Finished started event
Oct 26 23:30:59 htpc init: Handling started event
Oct 26 23:30:59 htpc init: event_finished: Finished started event

This indicates that udevtrigger is the last dependency of both 'gdm' and 'networking' to finish loading; I would normally expect this to finish sooner.  Do you have a lot of devices connected to this machine, or is the machine just very fast and finishes loading filesystems very quickly?

Please also post the contents of your /etc/network/interfaces file - one explanation for portmap not starting would be that the init scripts never see the loopback interface being brought up.