Problem with simple list example

Hi,

I'm using Flex SDK 4.5.0.17855 (Fri Sep 24, 2010).

<?xml version="1.0"?>

<s:Application

    xmlns:fx="http://ns.adobe.com/mxml/2009"

    xmlns:s="library://ns.adobe.com/flex/spark"

    >

    <s:RichText>

        <s:TextFlow>

            <s:list>

                <s:li>item</s:li>

                <s:li>item</s:li>

                <s:li>item</s:li>

            </s:list>

        </s:TextFlow>

    </s:RichText>

</s:Application>

At runtime, this gives me the following error:

ArgumentError: NewElement not of a type that this can be parent of

at flashx.textLayout.elements::FlowGroupElement/replaceChildren()

at flashx.textLayout.elements::FlowGroupElement/set mxmlChildren()

at flashx.textLayout.elements::TextFlow/set mxmlChildren()

at spark.components::RichText/createTextFlowFromContent()

at spark.components::RichText/commitProperties()

at mx.core::UIComponent/validateProperties()

at mx.managers::LayoutManager/validateProperties()

at mx.managers::LayoutManager/doPhasedInstantiation()

at mx.managers::LayoutManager/doPhasedInstantiationCallback()

Any ideas what to do to get this to compile?

cheers,

Jan