Are you getting any errors when executing the script? Is asIScriptContext::Execute returning asEXECUTION_FINISHED or something else?
Why is the Transform::position registered as a handle (@) when Transform::rotation and Transform::scalling aren't? Is the Transform class allocating the position member in the constructor?
I suggest you debug your code to make sure the script is actually having the correct reference to the Transform object in the Actor class.