I would just like to chime in that DDNS to dyndns.org was working for me prior to the 1.05 upgrade. Now it is updating every hour, regardless of the timeout value I enter in the config screen.
The point about NAT is well taken, but it was working before the 1.05 update.
Records from dyndns.org:
Jun-25 20:00:07 hostname=mark.is-very-bad.org
myip=70.73.XX.XX
wildcard=OFF
ez-update-3.0.11b7 mipsel-unknown-linux-gnu [] (by Angus Mackay) abuse
Jun-25 19:00:07 hostname=mark.is-very-bad.org
myip=70.73.XX.XX
wildcard=OFF
ez-update-3.0.11b7 mipsel-unknown-linux-gnu [] (by Angus Mackay) abuse
Latest timeout value tried: 56700 (hours)