Add to cart on category page.

[_dj]

Hello to all. i 'm making a site. I need a "add to cart" button on category page. i checked the http://forum.virtuemart.net/index.php?topic=90961.0 link but with this solution some time  "show cart" button doesn't show on pop up button. Pop up just show only continue shopping and name of product that has added.  I need a hint what i'm doing wrong. This is random error. how i can eliminate it.