Make sure that the recordset you are using to return the category is set to filter the category ID column on the CID URL variable that is being passed.
You wont be able to do a custom meta tag for the results page, but you can do this on the details page.
add a field to the products table for the meta tag, make sure the recordset on the details page returns the meta column and use that column binding from the recordset in the value of the meta tag.