"Error calling method on NPObject!" for flex deep linking

I have a flex app hosted on domain A and served through a webpage at domain B. I have enabled cross-domain scripting; in the webpage at domain B, I have the line

params.allowscriptaccess = "always";

and in the application code I have

flash.system.Security.allowDomain("*");

and for good measure,

flash.system.Security.allowDomain("keonehon.com"); // domain A

ExternalInterface calls seem to work; on startup the app calls a javascript function and the webpage calls a function back to pass a parameter in.

if (ExternalInterface.available){
                ExternalInterface.call("SWFLoadComplete");
                //lblMessage.text = "Data Sent!";
            }

function SWFLoadComplete(){
            callNewCarWithUser();
        }

        function callNewCarWithUser()
        {
          var user_id = document.getElementById('txtUserId').value;
          var room_id = document.getElementById('txtRoomId').value;
          getTheFlexApp().newCarWithUser(user_id, room_id);
        }

And this works correctly. So, yeah. Seems to be working fine, no?

HOWEVER, deep linking is not working, as setting the #state=____ flex param开发者_运维百科eter in the URL (either by typing something in, or by navigating backward using the back button) causes a javascript error to be thrown at line 435 of history.js, a.k.a.

getPlayer().browserURLChange(flexAppUrl); 

It seems like there is some sort of cross-domain security problem, even though I put in the line flash.system.Security.allowDomain("*");. You can see that there are different behaviors when same-domain vs. cross-comain by comparing two pages with identical html and swf files, just cross-domain in one case and same-domain in the other:

cross-domain: http://keonehon.com/gongos/dreamcar.html. same-domain: http://rails.mit.edu/gongos/dreamcar.html

What the heck is going on?

I'm not sure if this is related at all, but I use to get this error all the time with ExtJS and the problem actually ended up being a simple syntax error, (missing bracket ] )

Have you tried allowScriptAccess instead? (this might be case-sensitive if I remember correctly)

If that didn't work, it'd help to see more code or a sample page.