This is a know issue with the font dialog not working on OSX 10.6. It will be resolved when a new version of wxPython is released. There is nothing that can be done about it till a new version of the libraries Editra relies on are released, so please refrain from reporting this issue any further.
So when a version of Editra that officially supports OSX 10.6 is ready an announcement will be made.
Thanks,
Cody