If you are using the Windows or Mac version of our Dynamic Update Client, be sure you have placed check marks beside the hosts you would like to keep updated. If your using our Linux client, be sure you are only trying to update one host, or a GROUP of hosts (see the README.FIRST for more information on this).
Updates are only done when your IP address changes, not when it is different from what the host is currently set to. Your IP address must change for an update to be logged. In order to keep your No-IP Free account active (even if your IP address has NOT changed), you must update your host every 30 days. If your IP address has changed, then it has been updated and your account will be active for another 30 days. You can manually update your host by logging into your account and clicking update, or by clicking update from the Dynamic Update Client.