Do you absolutely have to use qTranslate to do it?
If not, read the official documentation for recommended method of translation:
http://docs.woothemes.com/document/woocommerce-localization/
Also try any plugin that is made to integrate with WooCommerce such as WPML.
Fixing compatibility between two plugins that is not integrated is not really worth the trouble. They are going to be updated continuously and you have to keep making changes to make them work together.