[support] Disappearing Part of URL and Breadcrumb

I'm working on a site that has a three level menu system, with two levels of menus and then page nodes under the second menu. When the third level page is clicked, on the second part drops out of the URL and breadcrumb, leaving just the first and third. So, for example, I have a top level menu called Products. Under that menu I have a page for each Category heading that describes the category. Then, I have a page for each individual product. In the menu, the category page is under the Products menu, and then each individual product page is under the Category page. So, the structure looks like this

Products |___Category |___Product 1 |___Product 2 |___Product 3

The problem is, when I navigate to Category, the URL and breadcrumb show as mysite.com/Products/Category (breadcrumb is Home->Products->Category), but when I click on the individual product page, the URL is mysite.com/Products/Product1, and the breadcrumb trail shows Home->Products->Product 1, instead of mysite.com/Products/Category/Product1 and Home->Products->Category->Product1, which is what I would expect.

Can anyone explain why this happens and any possible way to fix it?

Thanks.

Steve