ClickOnce not working on Firefox

I have a C# .net 2 win forms application that I want to publish with ClickOnce. The ClickOnce works perfectly on IE, but doesn't on Firefox开发者_开发问答 (my application manifest gets downloaded as an xml). I did some research and saw that .net 3.5 SP1 is required for Firefox to work with ClickOnce - I have .net 4.0 installed. What am I missing?

Thanks!

Be sure your MIME types are set correctly on your server.
http://robindotnet.wordpress.com/2010/06/12/mime-types-for-clickonce-deployment/

Also, there is a specific add-in for Firefox that does the same thing as the .NET 3.5 one; in fact it was created first.

Microsoft .NET Framework Assistant: https://addons.mozilla.org/en-us/firefox/addon/microsoft-net-framework-assist/

The ClickOnce team is gauging interest for a new FireFox plugin. Please reply to the thread over at github:Microsoft/dotnet/issues/185 to voice your interest.