Comment 2 for bug 979151

The issue is in filter.c

static GtkTreeModel *
activity_filter_model_new( GtkTreeModel * tmodel )
...
        { ACTIVITY_FILTER_DOWNLOADING, NC_( "Verb", "Downloading" ), GTK_STOCK_GO_DOWN },
...

etc

http://developer.gnome.org/glib/2.31/glib-I18N.html#NC-:CAPS
states:

"Only marks a string for translation, with context. This is useful in situations where the translated strings can't be directly used, e.g. in string array initializers. To get the translated string, you should call g_dpgettext2() at runtime. "

which the code doesn't do