"Error #3200: Cannot perform operation on closed window" received after window is closed, reopen again.

Steps to reproduce:
1. compile and run following code:
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:mx="library://ns.adobe.com/flex/halo"
xmlns:local="*"
creationComplete="openAWindow()"
close="myWin.close()">
<!-- test window is closed, set some properties, then reopen,
verify properties are changed
-->
<fx:Script>
<![CDATA[
import spark.layouts.BasicLayout;
import spark.components.Button;
import spark.components.Window;
import spark.components.CheckBox;
public var myWin:Window=new Window();
public function openAWindow():void
{
myWin.systemChrome="standard";
myWin.title="test window1";
myWin.status="this is a status";
myWin.layout=new BasicLayout();
myWin.width=300;
myWin.height=300;
myWin.open(true);
myWin.close();
}
public function toggleWindow():void
{
if (check1.selected)
{
myWin.width=400;
myWin.height=400;
myWin.alwaysInFront=true;
myWin.visible=true;
if (myWin.closed)
myWin.open(true);
check1.label="window opened";
}
else
{
if (!myWin.closed)
myWin.close();
check1.label="window closed";
}
}
]]
>
</fx:Script>

<s:CheckBox id="check1" x="130" y="150" label="close" click="toggleWindow()" />
</s:WindowedApplication>

2. when windowedApplication shows up, click checkbox
->window shows up
3. click checkbox, it will close the window.
->window is closed, which is expected.
4. repeat step 2, click checkbox to open the window again
->receive run time error:
Error: Error #3200: Cannot perform operation on closed window.
at Error$/throwError()
at flash.display::NativeWindow/get minSize()
at spark.components::Window/get minWidth()[E:\dev\trunk\frameworks\projects\airframework\src\spark\components\Window.as:843]
at spark.components::Window/set width()[E:\dev\trunk\frameworks\projects\airframework\src\spark\components\Window.as:947]
at window_close_open_issue/toggleWindow()[C:\work_flex_sdk\bugs\window2\src\window_close_open_issue.mxml:33]
at window_close_open_issue/__check1_click()[C:\work_flex_sdk\bugs\window2\src\window_close_open_issue.mxml:51]

Expected Results:

no error, repeat step 2~4, window should open/close as expected without any error.

Workaround (if any):