When adding the examples to the blog for Efflex I totally forgot why I usually only provide a link here instead of adding the movie to the post itself. Once this movie is running in a post, depending on whether you are viewing the front page, a category, the post itself etc, the URL to the source changes.
This is due to you only being able to specify a relative path to the source files using the export settings, you can try and specify the full path, but Flex Builder will strip out double forward slashes leaving a single forward slash. You could define it in AS but this would muddy the source.
ForceAbsoluteViewSourceURL.swc is a monkey patch of the Application class for Flex 3.0 which gets the URL of the SWF and appends this onto the relative path that was specified as the path to the source. This means it always has the same path, and therefore isn’t affected by the location of the HTML page its embedded in.
More Flex with the source enabled in blog posts! Hooray!