Yeah, I still think there's something quirky here. Consider the attached code.
If writeSharedObject() is called, and then another instance in the same domain
writes a different value to mySO.data.test, readSharedObject() will still
output "Hello world". The fix: add "mySO = null;" to the end of both functions,
or use local variables.

Obviously, this code is simplified for illustration purposes. Hope this is
helpful for someone else.

private var mySO:SharedObject;

private function writeSharedObject():void
{
mySO = SharedObject.getLocal("mySO", "/");
mySO.data.test = "Hello world";
mySO.flush();
mySO.close();
}

private function readSharedObject():void
{
mySO = SharedObject.getLocal("mySO", "/");
trace( mySO.data.test );
mySO.close();
}