I will try to clear this up for you.
On your pages with the add to cart server behaviors this session variable is set to the current page:
The code in the clear cart relies on this session variable value to redirect you back to the correct page. Checking the value of this session variable is the first step to debug why it is not returning you to the correct page. To print this value out you need to put in the following code on your cart display page since this is where we make use of this session variable.
The value of the continue redirect session variable is: <%= Session("WAEC_ContinueRedirect") %>
You should select a part of the page where you would like to see this value then go into code view and paste it into place. The next time you get to the cart page it should display this message and the value of the session variable. Please perform some testing on this by adding items to the cart and clearing the cart and let us know the results you are getting.