title: What are possible pitfalls when migrating from Flex SDK 4.0.0 to Flex SDK 4.1.0 (or later)?
body: <p>We have a large game built with Flex SDK 4.0.0, using Flex 4 as the GUI framework and (largely) PureMVC as the architectural framework.</p>
  
  <p>Since we need to add right-to-left text/layout support to the game in the near future and the <code>layoutDirection</code> property is only available in Flex SDK 4.1.0 or later, we obviously need to change the SDK with which we build our project.</p>
  
  <p>Are there any known pitfalls and issues that we could run into when making the switch? What are the things to keep a close eye one (ANT tasks? namespaces? custom components? charting?) because they could break during the migration?</p>