Problems With Objects, Argument.caller And SetTimeout

the structure of my source code is like this:

<script>
C = function(){
//some initialization
}

C.prototype.start = function{
//some action
setTimeout(arguments.caller.callee, "200");
}

var obj = new C();
obj.start();
</script>

This should execute the method start every 200 milisec, but (in some cases) it gives me an error because arguments.caller is null. Is there a "direct" method to use setTimeout without this arguments? stuff?

BTW: I'm working with IE Version >= 5.0

Is there a better solution to get start work?