Bug with leadingModel and alignmentBaseline

To help solve the problem of overlapping fonts (per post http://forums.adobe.com/thread/210312?tstart=90), I have been trying to adjust the baseline, leading, etc.  This setting seems to produce what I am looking for:

     textFlow.alignmentBaseline = TextBaseline.IDEOGRAPHIC_BOTTOM;
     textFlow.leadingModel = LeadingModel.IDEOGRAPHIC_TOP_DOWN;

However, an error happens when clicking the last line if all the text does not fit into the container.

TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at flashx.textLayout.elements::TextFlowLine/http://ns.adobe.com/textLayout/internal/2008::getRomanSelectionHeightAndVerticalAdjustment()
    at flashx.textLayout.elements::TextFlowLine/computePointSelectionRectangle()
    at flashx.textLayout.elements::TextFlowLine/http://ns.adobe.com/textLayout/internal/2008::hilitePointSelection()
    at flashx.textLayout.container::ContainerController/http://ns.adobe.com/textLayout/internal/2008::addSelectionShapes()
    at flashx.textLayout.compose::StandardFlowComposer/showSelection()
    at flashx.textLayout.edit::SelectionManager/addSelectionShapes()
    at flashx.textLayout.edit::SelectionManager/mouseDownHandler()
    at flashx.textLayout.container::ContainerController/mouseDownHandler()
    at flashx.textLayout.container::ContainerController/http://ns.adobe.com/textLayout/internal/2008::requiredMouseDownHandler()

I am using the release from 4/23/09 (Build 418).

Here is code to recreate the problem.  The problem happens when clicking on the last line.

public class TestTextLayoutCode extends Canvas {
    private var markup:String = "<TextFlow xmlns='http://ns.adobe.com/textLayout/2008'>" +
            "<p fontSize='48' fontFamily='Arial'>Very Big Font</p>" +
            "<p fontSize='12' fontFamily='Times New Roman'><span>" +
            "This is a normal font size to show how the text functionality works. " +
            "</span></p>" +
            "</TextFlow>";

    private var textFlow:TextFlow;
   
    public function TestTextLayoutCode() {
        textFlow = TextFilter.importToFlow(markup, TextFilter.TEXT_LAYOUT_FORMAT);
        textFlow.leadingModel = LeadingModel.IDEOGRAPHIC_TOP_DOWN;
        textFlow.alignmentBaseline = TextBaseline.IDEOGRAPHIC_BOTTOM;
        textFlow.flowComposer = new StandardFlowComposer();

        var container:Sprite = new Sprite();
        var controller:ContainerController = new ContainerController(container);
        controller.verticalScrollPolicy = ScrollPolicy.OFF;
        textFlow.flowComposer.addController(controller);
        controller.setCompositionSize(300, 80);
        rawChildren.addChild(container);
        textFlow.flowComposer.updateAllControllers();
       
        textFlow.interactionManager = new EditManager();
    }
}