On that topic of GTK, I've been using GTK on OSX on & off past couple of months & connecting fine. Even as an ultrapeer. I believe Birdy has had similar experience on Windows. But there's been several GTK updates over 12 months I believe. Which is great. The development on GTK went quiet for a while before that. Great to see there's enthusiasm back in developing GTK, it has a lot of pluses in my book. Particularly when run in advanced mode. Some of the options leave some other gnutella clients for dead.

GTK has a force-update approach. If you don't update your version won't work.