Hi prsetiadi,
In a response to your comment; all bugs I’ve mentioned and encountered were confirmed by WPML support and reproducible using standard theme and no other plugins installed.
I think WPML does not have a proper testing and release cycle – this might have changed over the past few months though since I’ve not used WooCommerce Multilingual since – and this leads to problems especially in an environment like WordPress where it is common for end-users to update their own installation.