When I set up Mahogany or select the preferences dialog, its contents do not appear. Sometimes I cannot enter anything in the fields.
wxGTK has a problem with constraint handling which can cause this dialog to sometimes get into an endless loop trying to do the layout. On most windowmanagers it helps if you resize the dialog a little and it will appear correctly. This seems to depend on the platform and windowmanager. Also, wxGTK does not seem to work correctly with OpenLook which does not allow you to enter anything.