I have no idea what that means. I don't even know what a query string is.
I didn't use a query string.
I only used the existing store admin menu on your test site.
I just created a product through the admin menu. And I created a category with an SEO item. And I put the product into the category. And now the category is not working.
See for yourself: go to http://www9.smith-consulting.com/
Then click on the people category.
Every product shows up. This is not correct.