rem: aAttachment.messageUri); 
add: aAttachment.messageUri, aAttachment.isExternalAttachment); 
context: function openAttachment(aAttachment){  messenger.openAttachment(aAttachment.contentType,                            aAttachment.url,                            encodeURIComponent(aAttachment.displayName),                            aAttachment.messageUri);}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/38ca496c7d84096946be40252c789bca175e28ba/msgHdrViewOverlay.js/buggy/mail/base/content/msgHdrViewOverlay.js