rem: aFeed.downloadCallback.downloaded(aFeed, kNewsBlogInvalidFeed); 
add: aFeed.downloadCallback.downloaded(aFeed, aFeed.request.status == 304 ? kNewsBlogNoNewItems : kNewsBlogInvalidFeed); 
context:   onParseError: function(aFeed)   {    if (aFeed && aFeed.downloadCallback)    {      if (aFeed.downloadCallback)        aFeed.downloadCallback.downloaded(aFeed, kNewsBlogInvalidFeed);      FeedCache.removeFeed(aFeed.url);    }  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/919c7ed69de90d3b7f17bb79d21e062103a7af3f/Feed.js/clean/mail/extensions/newsblog/content/Feed.js