qgis - spatial index intersection with qgsrectangle only computes polygones

I have the problem, that i only get polygon features inside my defined rectangle. If i switch off my polygon layer(s) i get my lines.

1. TOC: Line-Layer on, Polygon-Layer on: i only get Polygons which are inside


2. TOC: Line-Layer on, Polygon-Layer off: i get my lines which are inside.

In the tutorials, they say, that i will get all features which intersects my defined rectangle. If I use the index.nearestNeighbor function I will get poylgones and lines together. What did I wrong?

from qgis.gui import QgsMapTool
from qgis.core import QgsMapLayer,QgsPoint,QgsMapToPixel,QgsRectangle,QgsFeature, QgsFeatureRequest, QgsGeometry, QgsSpatialIndex
from PyQt4.QtGui import QCursor, QPixmap
from PyQt4.QtCore import Qt, QVariant
from qgis.utils import iface
import itertools

class NearestFeatureMapTool(QgsMapTool):


def __init__(self, canvas):
    super(QgsMapTool, self).__init__(canvas)
    self.canvas = canvas
    self.cursor = QCursor(Qt.CrossCursor)

def activate(self):
    self.canvas.setCursor(self.cursor)

def canvasReleaseEvent(self, mouseEvent):
    feat=QgsFeature()   

    for layer in self.canvas.layers():  
        if layer.type() != QgsMapLayer.VectorLayer:
            # Ignore this layer as it's not a vector
            continue
        if layer.featureCount() == 0:
            # There are no features - skip
            continue

        layer.removeSelection()


        # Determine the location of the click in real-world coords
        layerPoint = self.toLayerCoordinates( layer, mouseEvent.pos() )

        feature_dict = {feature.id(): feature for (feature) in layer.getFeatures()}

index = QgsSpatialIndex()
map(index.insertFeature,feature_dict.values())

#define rectangles
displayrectangle = self.canvas.extent()


#print displayrectangle.toString()
ownrectangle = QgsRectangle(layerPoint.x(),layerPoint.y(),layerPoint.x()+200,layerPoint.y()+200)

#print ownrectangle.toString()
if displayrectangle.contains(ownrectangle):
    userectangle = ownrectangle
else:
    userectangle = displayrectangle


# Auswahl der Features innerhalb des Rechteckes
for i in index.intersects(userectangle):
    print feature_dict[i].attributes() 

# -*- coding: utf-8 -*-

from qgis.gui import QgsMapTool
from qgis.core import QgsMapLayer,QgsPoint,QgsMapToPixel,QgsRectangle,QgsFeature, QgsFeatureRequest, QgsGeometry, QgsSpatialIndex
from PyQt4.QtGui import QCursor, QPixmap

from PyQt4.QtCore import Qt, QVariant
from qgis.utils import iface
import itertools


class NearestFeatureMapTool(QgsMapTool):
def __init__(self, canvas):

    super(QgsMapTool, self).__init__(canvas)
    self.canvas = canvas

    self.cursor = QCursor(Qt.CrossCursor)

def activate(self):
    self.canvas.setCursor(self.cursor)


def canvasReleaseEvent(self, mouseEvent):
     layerData = []
     feat=QgsFeature()
     index = QgsSpatialIndex()

     for layer in self.canvas.layers():
         if layer.type() != QgsMapLayer.VectorLayer:
            # Ignore this layer as it's not a vector
             continue

         if layer.featureCount() == 0:
    # There are no features - skip
             continue

         layer.removeSelection()


        # Determine the location of the click in real-world coords
         layerPoint = self.toLayerCoordinates( layer, mouseEvent.pos() )

         feature_dict = {feature.id(): feature for (feature) in layer.getFeatures()} 

         map(index.insertFeature,feature_dict.values())

    #define rectangles
         displayrectangle = self.canvas.extent()


     #print displayrectangle.toString()
         ownrectangle = QgsRectangle(layerPoint.x(),layerPoint.y(),layerPoint.x()+200,layerPoint.y()+200)

     #print ownrectangle.toString()
         if displayrectangle.contains(ownrectangle):
             userectangle = ownrectangle
         else:
             userectangle = displayrectangle


     # Print features inside my rectangle
         for i in index.intersects(userectangle):
             print feature_dict[i].attributes()