Echo Cancellation Issue

1

Hi there guys,
I have little issue with a live - conference application that i have developed using flex 4.5, now for a long time there were no issue but in last two weeks there has been major echo cancellation issue where in some instance echo cancellation does not work at all. what i noticed that it started happening after the update of flash player from 11.2 to 11.5 and also it generally occurs on macbooks. Below is the code where i get the microphone, let me know if some can help me resolve this issue.

public static function getMicrophone(index:int, echoSuppresion:Boolean):Microphone
{

        //trace ("echo " + echoSuppresion);
        var microphone:Microphone = Microphone.getEnhancedMicrophone(index);
        if (microphone != null && echoSuppresion) {
            var options:MicrophoneEnhancedOptions = new MicrophoneEnhancedOptions();
            options.autoGain = false; //was true before
            options.echoPath = 256;
            options.mode = MicrophoneEnhancedMode.FULL_DUPLEX;
            options.nonLinearProcessing = true; //was false before
            microphone.enhancedOptions = options;
            microphone.codec = SoundCodec.SPEEX;
            microphone.setSilenceLevel(5,10000);
            microphone.rate = 11;
            microphone.encodeQuality = 6;
        } else {
            microphone = Microphone.getMicrophone(index);
            microphone.rate = 11;
            microphone.encodeQuality = 6;
            microphone.setSilenceLevel(5,10000);
            microphone.codec = SoundCodec.SPEEX;
            traceOut("No AEC supported Microphone available, this will cause Echo. Please attach headphones to avoid.");
        }
        microphone.setUseEchoSuppression(true);
        _microphone = microphone;
        return microphone;
    }

Let me know what can i do to make this work again.