You're missing a plug-in with your initial Lion install.....the Java for OS X Lion download is available by clicking the "Missing Plug-in" link on the Ping Test.net page (just below the test pane). It should automagically take you into Software update to download the new feature.
Once the new Java software is installed you'll need to restart your browser in order to enable it. One of the nice features of the new Java package is that it will notify you when PingTest.net requests to use your computer for their test.
That did it. Mercy beaucoup!
