Hello everybody. Must report that the extension "Stop Autoplay" that in version 0.71 blocked silverlight in firefox now has been upgraded by the author to 0.72 and works OK with Silverlight.

 This is my Firefox configuration: (Silverlight works OK with this config!!!!!)

Firefox/2.0.0.11
Build ID: 2007112718

Enabled Extensions: [75]

• Adblock Filterset.G Updater 0.3.1.3 - Synchronizes Adblock with Filterset.G
• Adblock Plus 0.7.5.3 - Ads were yesterday!
• Add Bookmark Here 2 1.0.20070528 - Add a menuitem "Add Bookmark Here..." to Bookmarks Menu.
• All-in-One Sidebar 0.7.3 - Sidebar control with award-winning user experience!
• Auto Shutdown - InBasic 2.0.1C - Add Auto Shutdown PC after all downloads are finished to Firefox built-in download Manager.
• Backgroundimage Saver 0.1.2 - Save or View Backgroundimages (even if they are protected by hiding behind transparent Gifs).
• Bazzacuda Image Saver 2.0 - Batch saving of images opened in tabs.
• Better GCal 0.2.2 - Enhances Google Calendar with Greasemonkey user scripts.
• Better Gmail 2 0.2 - Enhances the new Gmail interface with Greasemonkey user scripts. Only compatible with the NEW Gmail interface.
• Bookmark Duplicate Detector 0.6.3 - Helps you find, move and remove duplicate bookmarks. It also notices you when you are adding a bookmark already in your Bookmarks.
• Bookmarks LinkChecker 0.6.8.4 - This extension checks links.
• Bookmarks Scrollbar 1.0.5 - Adds a scrollbar to the bookmarks menu
• Broadband Speed Test and Diagnostics 1.1 - Test speed of your broadband connections and provide troubleshooting
• Calculator 1.1.10 - A calculator with advanced features. Installed in the tools menu.
• Context Search 0.4.1 - Expands the context menu's 'Search for' item into a list of search engines.
• CustomizeGoogle 0.69 - Enhance Google search results and remove ads and spam.
• CuteMenus - Crystal SVG 1.9.1 - Adds icons to all menus.
• deskCut 0.5.0.5 - Create desktop shortcuts from the context-menu. Windows and Linux (KDE/GNOME) supported.
• Diccionario de Español/España 1.1 - Diccionario de Español/España
• Diccionario español Argentina 1.0
• DownloadHelper 2.5.3 - Download videos and images from many sites
• DownThemAll! 0.9.9.10 - The mass downloader for Firefox.
• DragNDrop Toolbars 0.0.0.6 - Your toolbars become Drag'N Dropable !
• Fancy Numbered Tabs 1.1 - Replaces the close tab graphic with numbers to help with quick tab navigation via CTRL + [1-9] or Alt + [1-9].
• Fasterfox 2.0.0 - Performance and network tweaks for Firefox.
• FEBE 5.1.1 - FEBE - Backup your Firefox data
• Firefox Search Sidebar 0.2.0.0 - Enjoy searching through multiple search engines with one query, and managing search plugins through one interface.
• FireFTP 0.97.1 - FTP Client for Mozilla Firefox.
• Fission 0.9 - Progress bar in the address bar (Safari style).
• FlashGot 0.7.2 - Enables single and massive ("all" and "selection") downloads using the most popular external download managers for Windows, Mac OS X, Linux and FreeBSD (dozens currently supported, see Extension's Home Page for details). FlashGot offers also a Build Gallery functionality which helps to synthetize full media galleries in one page from serial contents originally scattered on several pages, for easy and fast "download all".
• Flat Bookmark Editing 0.8.1 - Edit bookmarks in the bookmark organizer, without opening the properties window.
• Forecastfox Enhanced 0.9.5.2 - Get international weather forecasts and radar images and display it in any toolbar or statusbar with this highly customizable extension.
• FoxLingo 2.1.9 - The Ultimate Language Tool!
• Fullerscreen 2.3.1 - Really full screen...
• Gmail Space 0.5.92 - Use your Gmail account space for file storage. Enables uploading/downloading of folders.
• GMarks 0.9.7.3 - Shows your Google Bookmarks in the sidebar.
• Google Notebook 1.0.0.18 - Allows notetaking while browsing
• GoogleTabs 2.3 - Adds a context menu option to open Google search results in tabs. Compatible with the following searches: Web, Images, News, Groups, Froogle, Scholar, and Local; also compatible with Google Group homepages (Open All Topics) and Google News homepage (Open All News Articles).
• Grab and Drag 2.5.0.3 - Enables Adobe Acrobat-style grab and drag scrolling in Mozilla applications.
• GUtil! 2.1.9 - Google® Utilities in your Firefox Menu and Toolbar
• IE Tab 1.3.3.20070528 - Enables you to use the embedded IE engine within Mozilla/Firefox.
• IGoogle Sidebar 1.3.3 - View your IGoogle (Google Personalized Home page) modules in a sidebar
• Internote 2.1.5 - Persistent sticky notes for Firefox.
• MinimizeToTray 0.0.1.2006102615+ - Minimizes Mozilla windows into the system tray
• Mozilla Archive Format 0.6.3 - Save complete web pages in a single file.
• MR Tech Local Install 5.3.2.6 - Local Install power tools for all users. (en-US)
• NoScript 1.2.6 - Extra protection for your Firefox: NoScript allows JavaScript, Java (and other plugins) only for trusted domains of your choice (e.g. your home-banking web site). This whitelist based pre-emptive blocking approach prevents exploitation of security vulnerabilities (known and even unknown!) with no loss of functionality... Experts will agree: Firefox is really safer with NoScript :-)
• Organize Status Bar 0.5.2 - Organize your status bar icons.
• PDF Download 1.0.0.2 - Allows you to choose what to do with a PDF file: download it, view it with an external viewer or view it as HTML.
• Plain Text to Link 1.5.20061126 - Handle highlighted text with a right click!
• ReGet 1.0.1.307 - ReGet native plugin for Mozilla Firefox
• Remove Cookie(s) for Site 0.3 - Adds right-click menu option and toolbar button to remove all the cookies of currently opened site.
• Remove It Permanently 1.0.6.3 - Permanently hide items from the Context Menu
• Resizeable Form Fields 0.2.1 - Resize HTML form fields, including textareas, select boxes, and text fields.
• Sage 1.3.10 - A lightweight RSS and Atom feed aggregator.
• ScrapBook 1.3.2.5 - Helps you to save Web pages and organize the collection.
• Searchbar Autosizer 1.3.7 - Expand the searchbox as you type
• Shazou 1.2 - Shazou - we know WHERE... your server is!
• ShowIP 0.8.05 - Show the IP address of the current page in the status bar. It also allows querying custom services by IP (right mouse button) and Hostname (left mouse button), like whois, netcraft. Additionally you can copy the IP address to the clipboard. This extension was formerly known as ipv6ident.
• Skype extension for Firefox 2.2.0.70 - Skype extension for Firefox
• SmoothWheel 0.44.10.20071026 - Scrolls the document smoothly when scrolling the mouse wheel
• Split Browser 0.4.2007120601 - Splits browser window as you like.
• Stop Autoplay 0.7.2 - Disable the autoplay of the embedded music and movie.
• Stylish 0.5.3 - Customize the look of websites and of the user interface.
• Tab Mix Plus 0.3.6 - Tab browsing with an added boost.
• TableTools 0.22 - Sort, filter or copy any table ('ctrl+alt+click' sorts, 'ctrl+shift+click' shows filter, 'ctrl-z-click' etc. allows copying in various formats).
• Text Link 2.0.2007111301 - Allows URI texts written in webpages to be loaded by double clicks.
• TextMarker! 0.3.2 - Allows selected text to be highlighted via keyboard and context menu
• Tiny Menu 1.4.4 - Replace the standard menu bar with a tiny menu popup.
• Toolbar Buttons 0.4.5.2 - Adds toolbar buttons.
• toolbarmode 0.7.0 - Context menu to customize individual toolbars.
• Tor-Proxy.NET Toolbar 0.3 - Get Safety and Anonymity by using TOR-Proxy.NET for surfing!
• United States English Dictionary 2.0.0.6 - English United States (en-US) spellchecking dictionary
• UnPlug 1.6.06 - UnPlug your Plug-ins, free your Media
• Xippee Extension 2.3 - Xippee Extension

• Better Gmail 1.1.2 - Enhances Gmail with over 25 additional features. Works with the classic Gmail interface.
• easyGestures 4.1.2 - [en-US] - Mouse gestures within a popup pie menu.
• GTDInbox 1.33 - GTDInbox: Bringing GTD to Gmail
• KeyScrambler 1.3.2 - KeyScrambler protects you against keyloggers
• SaveURI 0.3.1.2 - Save the URI of every page for future reference.

• BlackX 2.0.1 - Feel the darkness!!
• BuuFirefox 2.0 - http://rafou.deviantart.com
• Firefox (default)
• GNOME 2.0.0 - GNOME for Mozilla Firefox
• Kempelton 2.0.3 - Clean, modern, easy to use icons.
• Kempelton 1.1 - Theme using the Kempelton icon set also seen in Thunderbird 2. Designed to be pleasant and functional.
• macbirdgraphite 1.0.2-20061202 - The clean look of Mac OS X Firefox 1.0 Graphite on your PC - includes UI elements and enhancements. Based on macfox graphite by Kelly Cunningham
• macfoxIIgraphite 2.1.4 - OSX Theme ported to PC
• My_buuf 1.0 - My_buuf Firefox 2.0 theme using icons from mattahan (http://www.buufdesigns.com)
• Qute 3.3.1 - Simple and unobtrusive theme with clear, colorful icons.
• Ubuntu Human Theme 2.0.4 - Firefox Ubuntu Human Theme
• Ubuntu Tango Theme 2.0.4 - Firefox Ubuntu Tango Theme

• 2007 Microsoft Office system
  - Office Plugin for Netscape Navigator
• Adobe Acrobat
  - Adobe PDF Plug-In For Firefox and Netscape
• DivX Player Netscape Plugin
  - npdivxplayerplugin
• IE Tab Plug-in
  - IE Tab Plug-in for Mozilla/Firefox
• Java(TM) Platform SE 6 U3
  - Java Plug-in 1.6.0_03 for Netscape Navigator (DLL Helper)
• Microsoft® Windows Media Player Firefox Plugin
  - np-mswmp
• Mozilla Default Plug-in
  - Default Plug-in
• QuickTime Plug-in 7.3.1
  - The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
• RealPlayer Version Plugin
  - 6.0.12.1739
• RealPlayer(tm) G2 LiveConnect-Enabled Plug-In (32-bit)
  - RealPlayer(tm) LiveConnect-Enabled Plug-In
• Shockwave Flash
  - Shockwave Flash 9.0 r47
• Silverlight Plug-In
  - 1.0.21115.0
• Windows Genuine Advantage
  - 1.7.0059.1

Nice!

(If this has answered your question, "Mark as Answer")

Shawn Wildermuth
C# MVP, MCSD, Speaker and Author

Silverlight 2 and 3 Workshop
Boston, MA: April 29 - May 1
Washington, DC: June 16-18th
http://silverlight-tour.com

are you trying to say.....

 .....install about 25 plugins and silverlight will work in firefox? i have almost no plugins installed on my firefox, yet my sample silverlight page is not working.

whats that all about? it loads but it doesnt render anyting? runs fine in IE browsers though.

we cannot get users to install or configure their browsers to have 25 plugins, a fools computer should be able to run silverlight!