The update is done using HTTPS, but it uses the invalid certificate that Zone Edit sends. This error seems to be caused by your Antivirus preventing the application from sending mail. It was truncating the last 2 digits of the IP address.
In conversations with Zoneedit technical support, this is apparently by design, and is not going to be changed. You will have to set it so that Zoneedit can send mail. I'm receiving an error along the lines of I was using the URL get the IP. If you are having a problem, you can contact me via e-mail at It should run fine. Neither Zone or myself take any responsibility if something does go wrong.
So I had to modify / expand my to work with both providers.
I wasn't really interested in the one, and after trying the Zone Edit program, I found it was a bit flaky (it would regularly not be able to find it's IP, etc).
The Zone Edit program is to be open source, and the source will soon be provided.
The instructions on how to make the request are laid out on Zone Edit's page about Dynamic DNS.
Using the information from this source, I was able to create my own (mostly) open source program. The name of the installed service is "Zone Edit Dynamic DNS Update" 2.