Abuse is when you change it too much
There were some devices that try to update something every minute and that was putting too much of a load on to the servers. You're suppose to only update when it's needed and it would seem to me that updating something once every 40 days if that's when the address changes is being a good citizen.
Here's a quote.
"To conserve resources, DynDNS uses a blocking mechanism to protect against excessive updating. DynDNS blocks update clients by useragent and will disable a user's hostname if it abusively updating.
Why Was I Blocked?
You needlessly updated a hostname too many times. The update client that you were using is abusing our DNS Update API and we block abusive clients to ensure quality service for all of us."
Ok but this is confusing.
"Updates should only be performed when your IP address has changed. We allow users to modify or "touch" their host every 28 days to prevent their hosts from expiring. Everything else is abusive."
Not sure what they mean by "touch". If they mean that if you try to resolve the name once every 28 days, then it will be kept alive, then that's good. I'm using a certified hardware client with Linksys so that should keep me safe.