to know which of them, just go to the websites www.myip.se and www.myip.dk and see who is replying wrong.
That is one of the first things I did yesterday. As I said before those addresses "might" be causing the problem. Today, I'm not to sure it is the case.
All I know for sure right now is that when HFS finds the wrong external address (the last digit of the real IP is missing), and when that invalid IP address shows up in the list of IP addresses in HFS, I
cannot access my no-ip account. So, I am almost sure there is a relationship between the external address found by HFS and the DNS Updater problem.
Do you not see a wrong external address from time to time in your HFS list of IP addresses? It is strange because sometimes HFS will find the correct external address and other times it won't (last digit of real IP is missing). The first time I noticed this problem is in beta 38. You are aware of the routines used when HFS finds an external address. I think the problem is there.