I'm experimenting with Flex and Rails right now (Rails is cool). I'm following the examples in the book "Flex on Rails", and I'm getting some puzzling and inconsistent behavior.

Heres the Flex MXML:

<mx:HTTPService id="index"
  url="http://localhost:3000/people.xml" resultFormat="e4x" />

<mx:DataGrid dataProvider="{index.lastResult.person}"
             width="100%" height="100%">

        <mx:columns>
            <mx:DataGridColumn headerText="First Name" dataField="first-name"/>
            <mx:DataGridColumn headerText="Last Name" dataField="last-name"/>
        </mx:columns>

</mx:DataGrid>

<mx:Script>
    <![CDATA[
        import mx.controls.Alert;

        private function main():void
        {
            Alert.show( "In main()" );
        }
    ]]>
</mx:Script>

When I run the app from my IDE (Amythyst beta, also cool), the DataGrid appears, but is not populated. The Alert.show() also triggers.

When I go out to a web browser and manually enter the url (http://localhost:3000/people.xml), the Mongrel console shows the request coming through and the browser shows the web response.

No exceptions or other error messages occur.

Whats the difference? Do I need to alter some OS setting? I'm using Win7 on an x64 machine.