I have not read this anywhere and it took me a while so here it is. Make sure that you are pointing your playerglobal.swc file to Flash Player 10, rather than 9 otherwise you will get these errors when you try and compile the application.Also, you will also need to have flash player 10 installed since some classes use the new text engine.

1046: Type was not found or was not a compile-time constant: ElementFormat.

1046: Type was not found or was not a compile-time constant: TextBlock.

Here is the Link to guide you.