typepad-ascii-filename.user.js

// ==UserScript==
// @name          Use ASCII-only filenames in TypePad
// @namespace     typepad
// @description   You need to go to Compose, click "Display Options" and enable "Filename" to use this script.
// @creator       Tatsuhiko Miyagawa
// @include       http://www.typepad.com/site/blogs/*/post/compose
// ==/UserScript==

window.addEventListener("load", function(e){
    YAHOO.util.Event.removeListener("name","keyup");
    YAHOO.util.Event.on("name", "keyup", function(e){
        this.form.filename.value = TC.Tools.dirify(this.value,{ ascii: 1 }).substr(0,100);
    });
});