TestRunnerBase compile error FX3 FU4

I am getting a compile error.
Using FlexBuilder3 (3.4.1 SDK).
FlexUnit 4
I have the 5 swc files in my project's lib folder.

Here is my code:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml"
                        xmlns:adobe="http://www.adobe.com/2009/flexUnitUIRunner"
                        layout="absolute" creationComplete="init()">
    <mx:Script>
        <![CDATA[
            import flexUnitTests.TestSuite;
            import org.flexunit.runner.FlexUnitCore;
            import org.flexunit.listeners.UIListener;

            private var core:FlexUnitCore;
           
            public function init():void {
                core = new FlexUnitCore();
                core.addListener(new UIListener(uiListener));
                core.run(TestSuite.ampTestSuite);
            }

        ]]>
    </mx:Script>
    <adobe:TestRunnerBase id="uiListener" width="100%" height="100%"  />
</mx:WindowedApplication>

This is the error:  Could not resolve <adobe:TestRunnerBase> to a component implementation.

(this question was also posted on an existing thread)

Please advise.
Roy P.