>From Adobe Flex 2: Training from the source: "Due to security constraints, History Management does not work in Internet Explorer when previewing a local file, meaning that it does not work when previewing local files on your hard drive. However, it will work if the file is on a web server or accessed through an HTTP URL as opposed to the file:// URL that is used during normal development. If you are using Intenet Explorer you will need preview these files from a web server. History Management does work in Firefox and Netscape browsers when previewing a local file"