Product duplication

Hello, I'm having an odd situation.

Unfortunately it's a super heavy modified Zen (I've even no idea which is the starting version, nor if it was english or italian..., now it should be a full 1.3.8 with various patches).

The problem is that in a category with 40 products one product come up 2 times. Same id. It only happens on frontend, the backend is ok (which it means that in backend this category has 44 products, 5 with status 0, so 39 active products and in frontend this category has 40 products, 39 ok + 1 which is the duplicated one).

I checked the occurrence of the product_id in these tables:

products
products_to_categories
products_description

and everything seems ok

1 in products, 1 in products_to categories (that product is placed only in that category), 4 in products_description (There are 4 languages in this store, and that product_id comes up 4 times, one for each language_id).

So I echoed the query in product_listing.php, obtaining a query that I launched over the db via phpmyadmin, obtaining as well that product 2 times.

So I compared (winmerge) default_filter.php with the default one, coming from a fresh distribution. NO diff, files are identical.

Now I've no more ideas.

Do you see something I'm missing?

Thanks in advance, Paolo

P.S. (unfortunately I'll be away next days (It' joomladay here in Italy and I'll be there)).

Look, via phpMyAdmin, in the table:
products_to_categories

pull up the matching products_id ... do you have 1 for this categories_id or duplicates?

You can have multiple categories_id per products_id but you should not see duplicates ...

Hi Linda, sorry for my late response, but i didn't receive the notification of you reply...

Unfortunately in products_to_categories there is just 1 occurrence of that product_id. Of course there must be something that duplicate that product, but I'm not able to find what it may be.

Fortunately this strange thing does not have a real bad impact, and so I may delay the investigation. Next step would be to dump involved tables in another db and eliminate unnecessary records and then study the query.

When I'll find the solution I'll post it here.

The next thing would be to compare the products table to the products_description table and that you just have 1 products_description per language for each products_id in the products table ...