The link you gave is to the same thread that we are in now. Post #26 of that page is the version of the mod that I posted. An earlier post in the same thread has the original version of the mod. You would use either one or the other, depending on how you want your store to work.
I am afraid that you're giving me more credit than is due. As I stated in previous posts, the only part I had in developing the version of the mod that I included in post #26 is that I hired someone to alter the original mod so that it would work when having separate Add to Cart buttons for each product. Though I have done some mods of my own, they were simple ones. A mod like this one is way beyond my ability to author since my knowledge of PHP is extremely limited.
That having been said, if you take a look at http://mdschoice.com/human_products/index.php?main_page=products_all, you'll see that the All Products page has the attributes and the same appearance and layout as the other product listing pages, so I know that the mod in this thread and the one in that thread I posted the link to can work in conjunction.
By a comment that you made, it sounds like you might have misunderstood what to do. The first thing you do is apply the mod in this thread and get your Product Listing page operating the way you want it to. Then you use that other mod to make All Products, New Products, Featured Products, etc. work the same way as your Product Listing page.
If you didn't before, I would recommend that you read that entire other thread. There are corrections, additions and explanations on later pages.
As a reminder, both of these mods were designed to work with Zen Cart 1.3.7. I don't know what version you have, but if it's a newer one, there may be issues of incompatibility.
mcqueeneycoins:
Maureen,
I gave it a shot but can't get it to work. I installed the single template but the add to cart and quantity boxes would not show up on the product listing pages. I tried adjusting the admin setting with no luck. I then tried to merge this mod (http://www.zen-cart.com/forum/showthread.php?t=98641&page=3) -- it just so happens to look like something you helped develop! -- thinking that would solve the problem and I got lost. I'm afraid PHP is not my strong suit. Would you be willing to give me a little more guidance on where to go from here? I want the quantity box, drop down attribute box and add to cart buttons to appear on all of the product listing pages so that it appears almost like this: https://www.mcqueeneycoins.com/index.php?main_page=index&cPath=1_2 (I have uninstalled the single template for now). You can see on the All Products page (https://www.mcqueeneycoins.com/index.php?main_page=products_all) there is no add to cart or attribute drop down.
Thanks again!