streaming audio with rtmp error

Hi all, I'm trying to build a radio stream player for my site and I'm having some issues, here's my actionscript and the error. Any help please?

rtmp://fcs_server_name/app_name/instance_name
So I'm getting a connection, but then I'm getting a weird error:
///////////////// OUTPUT ////////////////////////
> nc status > NetConnection.Connect.Success
The connection code is: NetConnection.Connect.Success
> ns status > NetStream.Play.Failed
>> Invalid tincan object name (stream ID: 1).
///////////////////////////////////////////////////////
Code:

nc = new NetConnection();
nc.onStatus = function(oInfo:Object):Void {
trace("> nc status > " + oInfo.code);
trace("The connection code is: " + oInfo.code);
};
nc.connect("rtmp://fcs_server_name/app_name/instance_name");

// create a stream with which the MP3 files
ns = new NetStream(nc);
ns.onStatus = function(oInfo:Object):Void {
trace("> ns status > " + oInfo.code);
trace(">> " + oInfo.description);
};
ns.setBufferTime(1)
//ns.play("index.flv", 0, -1, true);
ns.play("rtmp://fcs_server_name/app_name/instance_name",0,-1,true);