blender not saving the composited image

hello,

i need help,i am rendering a blend file on the server through command line using a script but blender is saves the image before
compositor starts working or i am not able to save the composited image from blender.

here is the code

import bpy
img = bpy.data.images.load(filepath="/var/cropped1361614908_1.jpeg")
bpy.data.textures[‘photo1’].image = img
img = bpy.data.images.load(filepath="/var/cropped1361614908_2.jpeg")
bpy.data.textures[‘photo2’].image = img
img = bpy.data.images.load(filepath="/var/cropped1361614908_3.jpeg")
bpy.data.textures[‘photo3’].image = img
img = bpy.data.images.load(filepath="/var/cropped1361614908_4.jpeg")
bpy.data.textures[‘photo4’].image = img
img = bpy.data.images.load(filepath="/var/cropped1361614909_5.jpeg")
bpy.data.textures[‘photo5’].image = img
bpy.ops.render.render()
bpy.data.images[‘Render Result’].save_render("/var/output/123.png")
bpy.ops.wm.quit_blender()

i only get a rendered image without any of the composited effects
any thoughts or workarounds.
i am using blender 2.65a
thanks