Upgrading from SDK 4.0 to 4.1 with Flex 3 compatibility mode causes the popup to be mirrored

Found in Flex 4.1.

Steps to reproduce:
1. Run attached Flash Builder project using the 4.0 SDK (make sure project properties are set to "Use Flex 3 compatibility mode").
2. Change the project to compile with 4.1 SDK.

Actual Results:
In 4.1 the popped up Panel is mirrored and the text disappears

Expected Results:
The 4.1 result should look the same as the 4.0 result (not mirrored).

Workaround (if any):
(a) In Flex 4.1, explicitly set the direction and layoutDirection to "ltr" (although this shouldnt be needed).

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:mx="library://ns.adobe.com/flex/mx"
creationComplete="init();"
layoutDirection="ltr" direction="ltr">

(b) Similarly, if you're using the older 2006/mx namespace, you could do something like this:

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" direction="ltr" layoutDirection="ltr">

(c) Set the direction/layoutDirection styles globally using a <Style/> block:

<mx:Style>
global

</mx:Style>