Drag & Drop between two SuperTabNavigators broken in Flex 4.6

[RaghuramDuraisamy]

What steps will reproduce the problem?
examples/SuperTabNavigator can be used to reproduce the problem.
Specifically, move a tab from SuperTabNavigator to the other

What is the expected output?
Original tab should be moved to the destination SuperTabNavigator.

What do you see instead?
An empty tab is added to the destination SuperTabNavigator.

What version of the product are you using? On what operating system?
Trunk as of 2nd August 2013. Windows 7.

Additional Information
Why do we have special handling for IList type in SuperTabNavigator.tabsReordered()? (Why do we create a new empty Canvas and add it to the destination navigator instead of moving the existing tab?)

ViewStack.as in Flex 4 implements ISelectableList and hence a type of IList. If above mentioned special handling can be removed, then that would fix the issue. If that cannot be done, order of check in if..else block (SuperTabNavigator.as, line number 859 to 885) have to be reversed to check for ViewStack first.