I'm having some problems with an Extended validation certificate on a site that isn't showing the green bar correctly in Firefox. Chrome and IE are working fine.
When I load the page the bar appears for a few seconds and then disappears when the page has fully loaded.
Someone mentioned it could be because of loading images over HTTPS, but I'm not sure how valid this case is. We have one image on the page that is loaded from another source over HTTPS, the rest of the images are stored in the file system on the server.
FYI - its Windows Server 2008 and ASP.net
UPDATE: Solved this problem - the style sheet was loading in a Google Font url using http, not https - changed it and now it's working.