I found a quite funny behavior in Visual Studio 2010 when working with Silverlight applications. The problem is that if your running Silverlight applications in Firefox it doesn’t clear the cache when loading your test page. End result is that your running an old version of the Silverlight code every time you debug.

A possible workaround is to change the browser used while debugging to Internet Explorer.

This is how you do it:

  1. Start a new Web site project (It can’t be done in a Silverlight project)
  2. Right click a webpage
  3. Select “Browse With”
  4. In the displayed dialog, select Internet Explorer
  5. Press the set default button
  6. Now close the dialog
  7. Open the Silverlight project

Now all debugging will open in Internet Explorer instead. Internet Explorer clears the cache when doing debugging, so you shouldn’t experience the problem.