The activation server is "http://wyday.com/limelm/...".
We'll be releasing TurboActivate 2.6 later tonight - it includes the ability to specify custom proxies. That is, you'll be able to make an interface in your app for the user to enter proxies.
As it is now, TurboActivate reads the proxies from the InternetExplorer settings. If those proxies don't work, it tries again without any proxy.