Parent Navigation Button error

Hi,

This happens only in the detail view page of a product. If i select the bar on the top left corner to go back to product listings, i get a 400 bad request page (product/%wpsc_product_category%/), like it can’t find the parent page. But the home button next to it works fine.

Thanks in advance.

https://www.ads-software.com/plugins/wp-e-commerce/