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: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/3590fb475dd5b57b4d0a31b64e31afecb2dfec1a/overrideHandler.js/buggy/suite/common/pref/overrideHandler.js