Media Server :: Calling Client Methods From (FMS 3.5)?

- Flash Media Server 3.5 (using ActionScript 3 for server-side code)

- Flex application (built in Flex Builder 3, using ActionScript 3)
 
Now, I'm trying to get the server-side ASC code to call something from a connected client.  It doesn't seem to work (thought everything else works beautifully).  I've tried stuff like the following in the server side:
 
- In the application.onConnect function, I've tried this:
 
...
currentClient.requestChat = function (reqID, destID){  trace("Requesting chat...");  currentClient.call("requestWaiting", new reqHandler(), reqID, destID);};
...
 
(Where reqHandler is just some handler that I know gets called).
 
- I've also tried the following code outside the onConnect function:
 
Client.prototype.requestChat = function (reqID, destID){  trace("Requesting chat...");  this.call("requestWaiting", new reqHandler(), reqID, destID);}

Both seem to fire appropriately (when triggered from another client).  However, the "requestWaiting" method call to the clients doesn't seem to work at all.  I've tried some AS 2 examples on the client side, like:
 
nc = new NetConnection();  nc.client = new Object();
// function for handling queueing of requests for this station  nc.client.requestWaiting = function (reqID:String, destID:String):void {        trace("HELLO");    // check to make sure this is the right location, and if so, queue it    if (destID == "WhateverTheIDIs") {    chatQueue.push(reqID);    btnChatWaiting.visible = true;    } // if        }
 
...but that doesn't seem to fire at all.  I know the Flex has "sealed" the NetConnection class itself, so I can't just "extend" it as I do the "client" property.I've als tried some more AS 3-oriented stuff, like trying to make the "client" property reference a separate class that handles callbacks, but that doesn't work easily for me as I need access to properties in the class that contains the NetConnection.