it depends only on pygtk version

src/cell_renderer_image.py

@@ -121,5 +121,5 @@ def on_get_size(self, widget, cell_area):
 					self.get_property('ypad'))
 		return x_offset, y_offset, calc_width, calc_height
 
-if gtk.gtk_version < (2, 8, 0) or gtk.pygtk_version < (2, 8, 0):  
+if gtk.pygtk_version < (2, 8, 0):  
 	gobject.type_register(CellRendererImage)