After several months of tinkering with GUI issues, I finally figured out how to correctly use Glade to generate Gtk interfaces (thanks to MonoDevelop source code). Then I was able to create GUI equivalent to the old one (Qt/C++).
I'm uploading the first working copy of mono sources into the "photogenie-sharp" module.
I'm not sure when next release will come as actually MonoDevelop stopped working after a mono/svn update (yep, I'm using latest mono sources on my SuSE box).
I just started PhotoGenie rewriting in C# for Mono. Hope I'll get a working version by the fall of this year.