microphone record, playback in AIR html js desktop app

this works on my macbook. But on my Windows 8.1 machine the audio gets played back twice as slow as normal.

Not a lower pitch, just twice as slow. Any idea why this is?

$(function(){

    var s;

    var sc;

    var nowRecording = false;

    var nowPlaying = false;

    var recordedBytes = new air.ByteArray();

//   air.SoundMixer.audioPlaybackMode = window.runtime.flash.media.AudioPlaybackMode.VOICE

    var mic = air.Microphone.getMicrophone();

    mic.rate = 44;

    mic.gain = 70;

    mic.setSilenceLevel(0);

    $("#btnRecord").click(function(){

        if (!nowRecording) {

            air.trace("recording");

            recordedBytes.clear();

            mic.addEventListener(air.SampleDataEvent.SAMPLE_DATA, getMicAudio);

            nowRecording = true;

            $(this).val("Click me to stop")

        }

        else {

            air.trace("recording stopped");

            mic.removeEventListener(air.SampleDataEvent.SAMPLE_DATA, getMicAudio);

            nowRecording = false;

            $(this).val("Click me to record")

        }

    })

    function getMicAudio(e){

        recordedBytes.writeBytes(e.data);

    }

    $("#btnPlay").click(function(){

        if (!nowPlaying) {

            air.trace("playing");

            recordedBytes.position = 0;

  s = new air.Sound();

            s.addEventListener(air.SampleDataEvent.SAMPLE_DATA, playAudio);

  sc = new air.SoundChannel

            s.play();

           sc.addEventListener(air.Event.SOUND_COMPLETE, stopPlayback, false, 0, true);

            nowPlaying = true;

          //  $(this).val("Click me to stop playing")

        }

        else {

            sc.stop();

            stopPlayback();

        }

    })

    function stopPlayback(e){

        air.trace("playing stopped");

        s.removeEventListener(air.SampleDataEvent.SAMPLE_DATA, playAudio);

        nowPlaying = false;

    }

    function playAudio(e){

  if(!recordedBytes.bytesAvailable > 0)

  return;

        for (var i = 0; i < 8192; i++) {

            var sample = 0;

  if(recordedBytes.bytesAvailable > 0) sample = recordedBytes.readFloat()

            e.data.writeFloat(sample);

            e.data.writeFloat(sample);

        }

    }

});