When trying to debug a Silverlight 4 application in Visual Studio 2010 with Firefox as my browser, I am unable to hit any breakpoints. I get the message "breakpoint will not currently be hit"

Here is the solution that worked for me when debugging was not working in Firefox:

1. Type "about:config" into the address bar of Firefox
2. Find the property named "dom.ipc.plugins.enabled"
3. Change the value from true to false by double clicking
4. Restart all Firefox browsers
5. Go back to Visual Studio and start debugging!

Hope this saves someone else some time!