Variations do not work

Hi,
Tried to set up some variations and none of them works …
I notice that the plugin creates some sub-products corresponding to these variations, so I went on an set a featured image for those than published them.
Still NOTHING happens on the main product, the image does not change according to the corresponding variation nor does the price change.
Looks different in your demo though, so which is the secret?

There are also no instructions as of how to set that up

Any help or should I drop it altogether?

Thx

http://ww.wp.xz.cn/plugins/orillacart/