I'm seeing some strange behavior with using states in Flex 4.1 with Flash 10.1. If a state contains an mx component, such as mx:FormItem, mx:DataGrid, etc., the state does not display any of the elements. The state changes, but nothing shows up. As long as their is one mx component is the state, no elements are visible. For example, If the mx:FormItem is replaced with s:HGroup or the mx:DataGrid is replaced with a s::List, the state loads all elements just fine. Very strange.
So, when I upgraded my Flex app from 4.0 to 4.1, I have to replace some mx components with spark alternatives to get the state to display its elements/components. It only takes one mx component to break it. The compiler shows no errors and runtime throws no errors... they just don't show up! So, my workaround was to change all mx to spark.
So, it appears state changes only work with spark components.
Haven't seen such an issue. Can you post a simple test case?