DG0 functions are plotted with reversed axes

Dear Dolfin developpers,

I think I have found a behaviour that looks like a bug to me.

I was trying to import data from a tiff image to a DG0 function. I was struggling to get the axes' orientation in agreement with he rest of my functions, when I realized that plotting a DG0 function produces a plot with its reversed compared to the same function projected on a CG1 space... Both x and y axis are reversed. I don't know about z, since I look at 2D data.

Here is a little piece of code, to be run with the attached image. Am I doing something wrong ? Isn't the DG0 image reversed ?
Thanks in advance for your help.

(This is on Dolfin 1.1.0 compiled with Dorsal on MacOS X 10.6.8)

import numpy
import dolfin
import Image

#input filename
file_im = 'image.png'

# input image
IM = Image.open(file_im)

# convert to numpy array
im = numpy.array(IM.getdata()).reshape(IM.size[1], IM.size[0]).astype(numpy.double)

# image size
Ly = 1e0
Lx = Ly*IM.size[0]/IM.size[1]
Ny, Nx = im.shape

# create mesh
mesh = dolfin.RectangleMesh (0, 0, Lx, Ly, Nx, Ny)

# load numpy array in DG0 image
V_DG0 = dolfin.FunctionSpace(mesh, "DG", 0)
I_DG0 = dolfin.Function(V_DG0)
I_DG0.vector()[:] = im[::-1,::].flatten().repeat(2) # repeat because we have two triangles per pixel

# project on CG1
V_CG1 = dolfin.FunctionSpace(mesh, "CG", 1)
I_CG1 = dolfin.project(I_DG0, V_CG1)

# plot => axes are reversed
dolfin.plot(I_DG0, title="DG0", axes=True)
dolfin.plot(I_CG1, title="CG1", axes=True)

dolfin.interactive()