rem: assertMIMEStuff(MIME_URI(this.mimeType), "fileExtensions", aExtensionString); 
add: assertMIMEStuff(MIME_URI(this.mimeType), "fileExtensions", aExtensionString.toLowerCase()); 
context:   addExtension: function (aExtensionString)  {    assertMIMEStuff(MIME_URI(this.mimeType), "fileExtensions", aExtensionString);  },
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/dbebec80bcbb69d03823c1a833161e871519695d/overrideHandler.js/clean/xpfe/components/prefwindow/resources/content/overrideHandler.js