Flex selectedItem problems - apache-flex

Question

I have encountered somthing a little strange in flex, possibly somthing im doing wrong
but im not sure.
In two cases which i have noticed, when there is only 1 item in a s:List or s:DropDownList
for some reason when using list.selectedItem it appears as null. Using requireSelection="true"
i know this isnt the case.
Has anyone else seen anything similar? or am i doing it completly wrong?
Thanks
Jon
Edit: In the code bellow it happens when clicking the edit document, which calls the open edit method
------------ Added Code ---------------------------
I have removed small portions to make it more readable
<s:TitleWindow width="486" height="300" title="Document Store"
xmlns:tmsbean="services.tmsbean.*"
close="close()">
<fx:Declarations>
<s:CallResponder id="getAllAttachedDocumentsResult"/>
<tmsbean:TMSBean id="tMSBean" showBusyCursor="true"/>
<s:CallResponder id="removeDocumentLinkResult" result="getDocumentList()"/>
</fx:Declarations>
<fx:Script>
<![CDATA[
private static var documentStoreView:DocumentStoreView = null;
[Bindable]
private var attachedToMenomic:String;
public static function getInstance():DocumentStoreView
{
if(documentStoreView == null){
documentStoreView = new DocumentStoreView();
DocumentForm.getInstance().addEventListener(DocumentFormEvent.DOCUMENT_ATTACHED,documentStoreView.getDocumentList);
}
return documentStoreView;
}
public function open(menomic:String,parent:DisplayObject):void
{
attachedToMenomic = menomic;
getDocumentList();
PopUpManager.addPopUp(documentStoreView,parent,true);
PopUpManager.centerPopUp(documentStoreView);
y = y - 80;
}
public function close():void
{
PopUpManager.removePopUp(documentStoreView);
}
private function getDocumentList(evt:DocumentFormEvent = null):void
{
getAllAttachedDocumentsResult.token = tMSBean.getAllAttachedDocuments(attachedToMenomic);
}
private function openEdit():void{
var editDsi:DocumentStoreItem = documentList.selectedItem as DocumentStoreItem;
Alert.show(editDsi.documentName);
DocumentForm.getInstance().openInEditMode(editDsi,this);
}
]]>
</fx:Script>
<s:VGroup left="10" top="10" right="10" bottom="10">
<s:List width="100%" height="100%" id="documentList" itemRenderer="com.documentStore.DocumentItemListRenderer"
dataProvider="{Utilitys.toArrayCollection(getAllAttachedDocumentsResult.token.result)}" />
<s:HGroup horizontalAlign="right" width="100%">
<s:Button label="Attach Document" click="{DocumentForm.getInstance().open(attachedToMenomic,this)}"/>
<s:Button label="Edit Document" click="openEdit()"/>
</s:HGroup>
</s:VGroup>
</s:TitleWindow>

Answer 1

By default Spark's DropDownList displays a prompt if selectedIndex is -1, which will be the case if requireSelection is false and you have not otherwise set the list to a specific item. This would correspond with selectedItem being null.
The Spark ComboBox does something similar but it has a TextInput as you can type into it.