Hi guys,
I understand the trouble here - but this is exactly what SecureDNS is supposed to do. If there is a device or configuration on the network (e.g. router) that modifies DNS resolves (such as instead of a porn site returns a blocked-page, or instead of your bank site returns a scam page), SecureDns is supposed to give you the right IP. What I see here is that it is working correctly. It is very hard to tell these two cases apart on our side - unless we would also provide the parental control part of the service.
Please, write me an email and I can (most probably) provide you with the current list of IPs used for Secure DNS at this moment - but this is a dynamic service, we add and remove servers based on their load, so it is not a static list.
It also shows, that any application that really needs to visit certain sites can do that, no matter what DNS server you have configured on the router. If we are talking about the computers you own and manage, then it seems to be that the best solution is really uninstalling SecureDNS. If we are talking about computers that you don't own and anyone can install any software on it (avast or other) - then blacklisting our IPs on the router would only help against SecureDNS, other methods of obtaining the DNS address similar to ours would still go through.
Lukas.