FlexUnit 4 error:adobe:TestRunnerBase

I'm getting an error with FlexUnit 4 that I am not able to find a solution for. Here is the error:

Could not resolve to a component implementation.

Here is my sample app (I am using FlashBuilder 4 Premium so I assume all necessary SWCs are already installed):

<?xml version="1.0" encoding="utf-8"?>

<fx:Declarations>
    <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>

<fx:Script>
    <![CDATA[

        import sampleSuite.SampleSuite;
        import org.flexunit.listeners.UIListener;
        import compilationSuite.SuitesToRun;
        import org.flexunit.runner.FlexUnitCore;

        private var core:FlexUnitCore;
        public function runMe():void {
            core = new FlexUnitCore();
            core.addListener( uiListener );
            core.run( sampleSuite.SampleSuite );
        }

    ]]>
</fx:Script>

<adobe:TestRunnerBase
    id="uiListener"
    width="100%"
    height="100%" />

The one idea I found is from FlexUnit support site and it says that if my namespace isn't wrong (and it isn't) then I'm missing this file: FlexUnit4UIListener.swc

I'm using FlashBuilder 4 and Flex 4.5.1 SDK. In my build path I'm referencing these three files and their SWCs:

C:\Program Files\Adobe\Adobe Flash Builder 4 Plug-in\eclipse\plugins\com.adobe.flexbuilder.flexunit_4.0.1.277662\flexunitframework\libs\version4libs{Common,FlexProject, and locale/version4locale}

Do I need more SWCs in my project's libs folder, too? What could I be missing?

I believe the issue must be something about importing the SWC files incorrectly. Regardless, I have upgraded to FlashBuilder 4.6 and found an article that shows me how to use FlexUnit4 and I've got it working without issue.

Here is the link to that article just in case someone else might find it usefule: http://www.adobe.com/devnet/flex/articles/flashbuilder4_tdd.html