During the implementation of gdk_window_set_icon() I used the following
code (which is disabled in cvs now) :

#if 0 /* to debug pixmap and mask setting */
      {
        GdkPixbuf* pixbuf = NULL;
        char name[256];

        pixbuf = gdk_pixbuf_get_from_drawable (NULL, pixmap, NULL, 0, 0, 0,
0, w, h);
	if (pixbuf)
          {
            num = (num + 1) % 999; /* restrict maximim number */
            sprintf (name, "c:\\temp\\ico%03dpixm.png", num); 
            gdk_pixbuf_save (pixbuf, name, "png", NULL, NULL);
            gdk_pixbuf_unref (pixbuf);
          }
        pixbuf = !mask ? NULL : gdk_pixbuf_get_from_drawable (NULL, mask,
NULL, 0, 0, 0, 0, w, h);
	if (pixbuf)
          {
            sprintf (name, "c:\\temp\\ico%03dmask.png", num); 
            gdk_pixbuf_save (pixbuf, name, "png", NULL, NULL);
            gdk_pixbuf_unref (pixbuf);
          }
      }
#endif

As far as I can see the GdkImage::mem is shared with the pixmap::bits
but for 1bit depth images their representation is different (bits
mirrored) This gives the undesired effect shown in attachment one,
whereas it should look like attachment two (yes it is Wilber ;-)

Any hints how to fix this ?