Lots of folks are starting to notice that changes between Firefox 2 and Firefox 3 are causing failures in the isInstalled function used in older Silverlight.js files. Since the Silverlight.createObject function uses isInstalled, this results in Silverlight content being blocked on Firefox 3. Instead of seeing the content they expect, users are being asked to install Silverlight over and over again. The Silverlight 2 Beta 2 SDK offers an updated Silverlight.js file which includes an updated isInstalled method that covers the Firefox 3 scenario. To make your site Firefox 3 ready, download the new SDK and replace your existing Silverlight.js file with this updated version. Be sure to test your site thoroughly, however. We have made some changes in the updated Silverlight.js file which may impact your site's behavior.