can't publish in FMS 3.5

hi every body
I'm using FMS long time ago and I did a lot of work with it. My problem now when I started in my new project I could not able to hear the stream, the stream not recorded on server at all ... I just got a flv file with the stream name and its size just some bytes
Actionscript 3.0 code:
------------------------------
var stream:NetStream = new NetStream(connection);
stream.attachAudio(Microphone.getMicrophone());
stream.publish("flash_stream", "record");
-----------------------------------------
of course I have an opened connection to the server :)

FMS application code:
---------------------------------
application.onConnect = function( client) {
application.acceptConnection( client );
}
-----------------------------
so simple :)

Receiving flash Actionscript 3.0 code (the movie which get the stream):
-----------------------------------------------------------------
var stream:NetStream = new NetStream( connection );
stream.client = new CustomClient();
videoObject.attachNetStream( stream );
stream.play( "flash_stream" );
---------------------------------------------

Please every one ... it is very important ... I don't know why this not work right now :(

I have an old application and unfortunately it works fine at the same server.