Android :: Media Recorder Class Setting Audio Source / Unsupported Parameter

I'm new in Android development and I have the next question/problem. I'm playing around with the Media Recorder class to record just audio from the microphone. I'm following the steps indicated in the official site:
http://developer.android.com/reference/android/media/MediaRecorder.html

So I have a method that initializes and configure the MediaRecorder object in order to start recording. Here you have the code:
this.mr = new MediaRecorder();
this.mr.setAudioSource(MediaRecorder.AudioSource.MIC);
this.mr.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
this.mr.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
this.mr.setOutputFile(this.path + this.fileName);
try { this.mr.prepare();
} catch (IllegalStateException e) { Log.d("Syso", e.toString());
e.printStackTrace();
} catch (IOException e) { Log.d("Syso", e.toString());
e.printStackTrace();
}

When I execute this code in the simulator, thanks to logcat, I can see that the method setAudioSource(MediaRecorder.AudioSource.MIC) gives the next error (with the tag audio_ipunt) when it is called:
ERROR/audio_input(34): unsupported parameter: x-pvmf/media-input-node/cap-config-interface;valtype=key_specific_value
ERROR/audio_input(34): VerifyAndSetParameter failed

And then when the method prepare() is called, I get the another error again:
ERROR/PVOMXEncNode(34): PVMFOMXEncNode-Audio_AMRNB::DoPrepare(): Got Component OMX.PV.amrencnb handle

If I start to record by calling the method start(). I get lots of messages saying:
AudioFlinger(34):RecordThread: buffer overflow
Then after stop and release, I can see that a file has been created, but it doesn't seem that it been well recorded. Anyway, if I try this in a real device I can record with no problems, but I CAN'T play what I just recorded. I guess that the key is in these errors that I've mentioned before.