DK2 - ovrHmd_BeginFrameTiming called multiple times.

Hey guys!

first post here, so I apologize if Im posting in the wrong topic.

I´m trying to build an application using both libcinder and the oculus rift sdk2 by following the "Minimal Oculus Application" tutorial. After some tries linking the libraries I managed to make the application build. Now the problem is that, following the code from the tutorial I get this exception: Assert: ovrHmd_BeginFrameTiming called multiple times.

If I run on release mode, the exception is not thrown, but I dont get any info from the device either.

here is my code:

#include "cinder/app/AppNative.h"
#include "cinder/gl/gl.h"

#include "OVR_CAPI.h"
#include "Kernel\OVR_Math.h"

using namespace ci;
using namespace ci::app;
using namespace std;

class OculusApp : public AppNative {
  public:
	void setup();
	void shutdown();
	void mouseDown( MouseEvent event );	
	void update();
	void draw();


	// Oculur Objects ------ 
	ovrHmd mHmd;
	ovrFrameTiming frameTiming;

};

void OculusApp::setup()
{
// cinder setup class, this is called once at the begining

	ovr_Initialize();
	mHmd = ovrHmd_Create(0);

	if(!mHmd){

		console() << "could not initialize" << endl;
		return;
	}

	ovrHmd_ConfigureTracking(mHmd, 1, 0);


	while(mHmd){
		frameTiming = ovrHmd_BeginFrameTiming(mHmd, 0); 
		ovrTrackingState ts = ovrHmd_GetTrackingState(mHmd, frameTiming.ScanoutMidpointSeconds);

			if (ts.StatusFlags & (ovrStatus_OrientationTracked | ovrStatus_PositionTracked)) {
				// The cpp compatibility layer is used to convert ovrPosef to Posef (see OVR_Math.h)
				OVR::Posef pose = ts.HeadPose.ThePose;
				float yaw, pitch, roll;
				pose.Rotation.GetEulerAngles<OVR::Axis_Y, OVR::Axis_X, OVR::Axis_Z>(&yaw, &pitch, &roll);

				console() << "yaw: "   << OVR::RadToDegree(yaw)   << endl;
				console() << "pitch: " << OVR::RadToDegree(pitch) << endl;
				console() << "roll: "  << OVR::RadToDegree(roll)  << endl;
			

				Sleep(150);
	
				ovrHmd_EndFrameTiming(mHmd);

			}
	}

}

the same happens if I put ovrHmd_EndFrameTiming(mHmd) outside the "if" bracket. the exception is not thrown, but no info either...

any help?
thanks!