I think the guilty portion is in comments_extension.rb, activate method:
if admin.respond_to? :page
admin.page.edit.add :parts_bottom, “edit_comments_enabled”, :before
admin.page.index.add :sitemap_head, “index_head_view_comments”
admin.page.index.add :node, “index_view_comments”
It seems like maybe it should test for something other than responding
to :page. Or perhaps it’s calling the activate method more than once,
and it’s not supposed to.