Update: A new beta version of the 1.5 series has again finally been released. The new DNS service providers all-inkl.com and inwx.com are supported and some code refactoring to support custom DNS and IP service providers has been performed. My plan is to have custom provider support and multiple account support for a 2.0 release this year.
There have been some reports about issues with the Updater not updating anymore. Please try the latest beta version and switch to another IP Check provider instead of the previous default dnsomatic.com. For some reason they are rate-limiting the number of requests to their service. The new IP Check provider selection allows you to choose another provider in such cases. You can test the functionality with the new "Test" panel.
I just upgraded to 126.96.36.1994, and am getting badauth messages instead of IP updates. I did an upgrade through the software (it prompted for the upgrade). I re-entered all my information, and now it's not even trying.
Please update to 188.8.131.525. There was a small mistake inside the wireless network filtering check. Sorry for the inconvenience. From which version did you upgrade?