If the box says that you are using random ports, there is nothing to worry about. If it shows a red border, your resolver does not use completely random source ports. This could imply a security problem; see the following CERT advisory. However, some resolvers have implemented countermeasures that do not solely rely on random source sources.
There is a little bit more information about this security problem on Dan Kaminsky's blog.
You can add this test to your own page: