Body Movement + rotation issue

Hi,
i've implementend body movement with GLUT for my avatar with w,s,a,d keys. When i turn my head or move the body of my avatar separately it works very well, but doing the two actions combined it's easy to notice a huge "shaking" in the camera movement causing a very disturbing motion sickness.

This is how i calculate my modelviewmatrix and how i set up it on my two cameras:

 float HeadPitch, HeadRoll, HeadYaw;
	 OculusVR->getEyePosition(&HeadYaw,&HeadPitch, &HeadRoll);

	ovrFrameTiming hmdFrameTiming = ovrHmd_BeginFrame(OculusVR->HMD, 0);

	 EyePos.y = ovrHmd_GetFloat(OculusVR->HMD, OVR_KEY_EYE_HEIGHT, EyePos.y);
	//Move on Eye pos from controls
    OVR::Matrix4f yawRotate = OVR::Matrix4f::RotationY(HeadYaw);

	Vector3f orientationVector = yawRotate.Transform(localMoveVector);
	
    orientationVector *= MoveSpeed;
	EyePos += orientationVector;


	   for (int eyeIndex = 0; eyeIndex < ovrEye_Count; eyeIndex++)
		{	   
		 OculusVR->eye = OculusVR->HMDDesc.EyeRenderOrder[eyeIndex];
		 OculusVR->eyeRenderPose[OculusVR->eye] = ovrHmd_BeginEyeRender(OculusVR->HMD, OculusVR->eye);
		 OVR::Quatf culo= OculusVR->eyeRenderPose[OculusVR->eye].Orientation;

			OVR::Matrix4f finalRollPitchYaw  = OVR::Matrix4f(culo);
			OVR::Vector3f finalUp            = finalRollPitchYaw.Transform(Vector3f(0,1,0));
			OVR::Vector3f finalForward       = finalRollPitchYaw.Transform(Vector3f(0,0,-1));
			OVR::Vector3f shiftedEyePos      = EyePos; //+ OculusVR->eyeRenderPose[OculusVR->eye].Position;
			
            OVR::Matrix4f view = OVR::Matrix4f::LookAtRH(shiftedEyePos,shiftedEyePos + finalForward, finalUp); 
		   OVR::Matrix4f proj = ovrMatrix4f_Projection(OculusVR->EyeRenderDesc[OculusVR->eye].Desc.Fov, 0.01f, 10000.0f, true);

		   if(eyeIndex == 0)
		   {
		 	beginEditCP(leftCamera);
				leftCamera->setProjectionMatrix(OVRtoOSG(proj));
				viewm = OVRtoOSG(OVR::Matrix4f::Translation(OculusVR->EyeRenderDesc[OculusVR->eye].ViewAdjust) * view);
				leftCamera->setModelviewMatrix(viewm);
			endEditCP(leftCamera);
		   }
		   else 
		   {
			beginEditCP(rightCamera);
			rightCamera->setProjectionMatrix(OVRtoOSG(proj));
				viewm = OVRtoOSG(OVR::Matrix4f::Translation(OculusVR->EyeRenderDesc[OculusVR->eye].ViewAdjust) * view);
				rightCamera->setModelviewMatrix(viewm);
			endEditCP(rightCamera);
		   } 
ovrHmd_EndEyeRender(OculusVR->HMD, OculusVR->eye, OculusVR->eyeRenderPose[ OculusVR->eye], &EyeTexture[ OculusVR->eye].Texture);
	}
	    localMoveVector.x=0;
	localMoveVector.y=0;
	localMoveVector.z=0;

glDisable(GL_CULL_FACE);
 glDisable(GL_DEPTH_TEST);
    ovrHmd_EndFrame(OculusVR->HMD);
	  glEnable(GL_CULL_FACE);
	glEnable(GL_DEPTH_TEST);
	glUseProgramTROIA(0);
}

And this is the GLUT part of my code, which reacts to key inputs:

void keyboard(unsigned char k, int x, int y)
{
   switch(k)
    {	
       case 27:        
        {
           exit(0);
        }
        break;

		case  115:
	{
                 localMoveVector.z=1;
			}
		break;

		case  119:
		{			
	 localMoveVector.z=-1;
		}
		break;
			case  97:
			{
   localMoveVector.x=-1;
			}
		break;
			case  100:
		{
   localMoveVector.x=1;
}
		break;
    }
}