Has anyone noticed odd behaviour with vil_crop()?

I'm noticing that in a very simple program the followning lines of code produce the same output image:

  vil_image_view<PixelType> cropped_image = vil_crop(img_in, 0, 128, 0, 128);
  vil_save(cropped_image, ofname().c_str() );

OR

  vil_image_view<PixelType> cropped_image = vil_crop(img_in, 56, 128, 136, 128);
  vil_save(cropped_image, ofname().c_str() );

The result for either pair of lines give the same output image.  The output image begins at i0=j0=0 in the original image and is 128x128.  It's as if i0 and j0 are ignored.  Has anyone else seen this behavior?

Glen Brooksby