Hello, I use gnumeric-1.12.31 on GNOME, and i don't have this problem.
I am hitting a similar problem with gnumeric. Install latest, open spreadsheet, hit 'safe as' and you get: (gnumeric:1974): GLib-GIO-ERROR **: Settings schema 'org.gtk.Settings.FileChooser' is not installed (bit annoying as some work got lost) but easy to reproduce. This issue suggests a solution: http://stackoverflow.com/questions/9678301/can-not-use-gtk3-filechooser-on-mac-osx#9684626 i.e., the builder needs to run glib-compile-schemas [path to org.gtk.Settings.FileChooser.gschema]. There is a compiled schema in the path, but maybe not for FileChooser and others.
