I'm sorry, but isn't the Belkin WeMo smart switch only compatible with 110V 60Hz power lines? Even if it was installed correctly, does it function correctly on 220V 50Hz power lines?
Also, if I were you, I would stick to the wiring diagram or wiring instructions which usually come with the product. A picture of the switch itself would be great (you put a link to a standard US configuration switch, is that what you have or is the product you bought of a different country configuration?). You can tell from the product model number.
Furthermore, I think the link on the official website would help you out in figuring the proper connections:
http://belkin.force.com/Articles/articles/en_US/Troubleshooting_and_Tutorials/9342#A
Quick edit, never ever connect the neutral line to the grounding line.