Using SetOrbitMode To Mimic Rotation

Can someone check this out and offer any pointers? The following code makes my camera mimic another client's player object for BOTH position and rotation, but the x-rotation (up-down) is choppy for some reason.

In game/camera.cc...

void Camera::processTick(const Move* move)
{
.
.
.
  if(mode == OrbitObjectMode || mode == OrbitPointMode)
  {
     if(mode == OrbitObjectMode && bool(mOrbitObject)) 
     {
        GameBase *castObj = mOrbitObject;
	Player* shape = dynamic_cast<Player*>(castObj);
        if( shape != NULL ) 
        {
           MatrixF ret;
           shape->getRenderEyeTransform( &ret );
	   mRot = ret.toEuler();
	   mPosition = ret.getPosition();
        }  
     }
	 setPosition(mPosition, mRot);
	 pos = mPosition;
  }
.
.
.
}

void Camera::interpolateTick(F32 dt)
{
.
.
.
  if(mode == OrbitObjectMode || mode == OrbitPointMode)
  {
     if(mode == OrbitObjectMode && bool(mOrbitObject)) 
     {
        GameBase *castObj = mOrbitObject;
	Player* shape = dynamic_cast<Player*>(castObj);
        if( shape != NULL ) 
        {
           MatrixF ret;
           shape->getRenderEyeTransform( &ret );
	   rot = ret.toEuler();
	   mPosition = ret.getPosition();
	}  
     }
	 setRenderPosition(mPosition, rot);
  }
.
.
.
}

Perhaps the issue has to do with the x-rotation being tied to the player's HEAD rotation, as opposed to the z-rotation which is probably tied to the BODY rotation. Or perhaps I need to add an extra step to calculating the deltas?