In shops using keywords, clicking on a tag presents a list of items correctly from the filtered selection however clicking on "Buy" gives an error message: "invalid URL" on a page with incomplete address to the item of interest" http://maxxebiz.com/silverzone.fb/online_shop/online_shop.php?category=
You may try:
http://maxxebiz.com/goodstore
http://maxxebiz.com/silverzone.fb/
I have had to stop offering this feature to shop customers as the end purpose of buying "the found item" using keywords does not work