reproduced with Inkscape 0.47+devel r8941 on OS X 10.5.8
If I change the UI language via 'Preferences > Interface > Language', Inkscape ignores the custom default template '~/.config/inkscape/templates/default.svg' and uses the localized system default template. To still load a custom default template from '~/.config/inkscape/templates' the file needs to be named corresponding to the locale used for the UI (default.{locale}.svg).
reproduced with Inkscape 0.47+devel r8941 on OS X 10.5.8
If I change the UI language via 'Preferences > Interface > Language', Inkscape ignores the custom default template '~/.config/ inkscape/ templates/ default. svg' and uses the localized system default template. To still load a custom default template from '~/.config/ inkscape/ templates' the file needs to be named corresponding to the locale used for the UI (default. {locale} .svg).