User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.5) Gecko/20031007 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.5) Gecko/20031007 www.mozilla.org and www.slashdot.org have icons by their URL in the location bar. When I load these sites in tab-less windows, their icons appear. On adding a new tab to these windows, the icons disappear. Reproducible: Always Steps to Reproduce: 1.open new browser window, no tabs. 2.go to site with a favicon.ico or 'link rel="icon"' icon 3.open new tab in this window. icon disappears from tab and from location bar (4.if loading a site with icon in new tab, its icon appears fine) Actual Results: The first of the 2 tabs in the window has no icon by its location or in the tab title. (If loading a site with an icon, that appears) Expected Results: The first tab should retain its icon, the new tab will load an icon depending on the site it is navigating. theme: modern installed extensions: uk-gb language and MozGuest

I'm quite sure that this is another dupe of bug 109959 - there is a whole bunch of things you can do to make the favicon disappear. I'm convinced that all of them have the same root cause. *** This bug has been marked as a duplicate of 109959 ***