conflict with jigoshop plugin?

Hi,
when I try to use EPS with jigoshop, I get a fatal error :

Fatal error: jigoshop_cart::calculate_cart_total() [jigoshop-cart.calculate-cart-total]: The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "jigoshop_product" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition in /xxxxxxxx/wp-content/plugins/jigoshop/classes/jigoshop_cart.class.php on line 507

I tried with a default theme and only these two plugins, same problem.

Any ideas?

Thanks

https://www.ads-software.com/plugins/easy-wp-parallax-slider/