Quote Originally Posted by raimond View Post
... When someone put something in the cart from a categorypage and the clicks the button "continu shopping" and add another product in the cart, the firtst product is now twice in the cart and the last one isn't. ...
I am unable to duplicate this in a stock installation of Zen Cart 1.5.x with the latest version of "Ultimate URLs" installed...

Tested with "Display Product Add to Cart Button = 1" and "Display Multiple Products Qty Box Status = 1, 2, or 3"
Tested with "Display Product Add to Cart Button = 2" and "Display Multiple Products Qty Box Status = 0"

In both cases the correct product was added to the order and no extra products were added to the order.

Quote Originally Posted by raimond View Post
...
I think it has to do something with the url created after "continu shopping"....the url looks like this "http://www.domain.com/onecat/?products_id=12431&sort=20a" ...
The "query terms" such as products_id are not added by this module (Zen Cart's core and your template control these).

Are you running an older version of Zen Cart or this module? How is your store different from a stock Zen Cart installation?