Permalink setup problem

Dear Sir,
I setup permalink in http://www.westones.com/stone
1, if CUSTOM URL: /stone/%product_cat%/ in “Shop base with category”
Sub-category display “Page not Found” mistake, other main-catogery and product page is correct.
2, If CUSTOM URL: /stone/ in “Shop base”
Product page dispaly “Page not Found” mistake, main-categery and subcategory are correct.
At present, I setup in “Shop base”.
What is happened?

Kindest regards