I had the same problem with 2 dynamic adsl connections. Although I would very much like to see in future releases the ability to have multiple dynamic dns clients, I have temporarily tried the following workaround. There are 2 always-on servers which have a dyndns client running. These 2 servers are forwarded to a different gateway with a netbalancer rule. As a result one dyndns client updates the first account and the other client the second account.