If you have osCommerce Hosting Catalog installed on your domain & you're facing the "1054 - Unknown column 'xxx.products_id' in 'on clause'" error on the site, which is basically a PHP/Mysql error or rather a bug in osCommerce..follow these steps quickly to get it fixed for sure

First, open "index.php" from the catalog in a text editor & do the following changes in it:

1. Replace all the p.products_id = s.products_id with p2c.products_id = s.products_id and in case if you're still getting the error: 1054 - Unknown column 'p2c.products_id' in 'on clause' then look for the line (NOTE: there are two lines starting with "//We show them all" comment & you have to go for the first one...)

CHANGE FROM:
// show the products of a specified manufacturer
if (isset($HTTP_GET_VARS['manufacturers_id'])) {
if (isset($HTTP_GET_VARS['filter_id']) && tep_not_null($HTTP_GET_VARS['filter_id'])) {
// We are asked to show only a specific category
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['manufacturers_id'] . "' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$HTTP_GET_VARS['filter_id'] . "'";
} else {
// We show them all
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and pd.products_id = p.products_id and pd.language_id = '" . (int)$languages_id . "' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['manufacturers_id'] . "'";
}
} else {
// show the products in a given categorie
if (isset($HTTP_GET_VARS['filter_id']) && tep_not_null($HTTP_GET_VARS['filter_id'])) {
// We are asked to show only specific catgeory
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from " . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['filter_id'] . "' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$current_category_id . "'";
} else {
// We show them all
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_PRODUCTS . " p left join " . TABLE_MANUFACTURERS . " m on p.manufacturers_id = m.manufacturers_id, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$current_category_id . "'";
}
}
TO:
// show the products of a specified manufacturer
if (isset($HTTP_GET_VARS['manufacturers_id'])) {
if (isset($HTTP_GET_VARS['filter_id']) && tep_not_null($HTTP_GET_VARS['filter_id'])) {
// We are asked to show only a specific category
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from (" . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c ) left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['manufacturers_id'] . "' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$HTTP_GET_VARS['filter_id'] . "'";
} else {
// We show them all
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from (" . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m) left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and pd.products_id = p.products_id and pd.language_id = '" . (int)$languages_id . "' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['manufacturers_id'] . "'";
}
} else {
// show the products in a given categorie
if (isset($HTTP_GET_VARS['filter_id']) && tep_not_null($HTTP_GET_VARS['filter_id'])) {
// We are asked to show only specific catgeory
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from (" . TABLE_PRODUCTS . " p, " . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_MANUFACTURERS . " m, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c) left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.manufacturers_id = m.manufacturers_id and m.manufacturers_id = '" . (int)$HTTP_GET_VARS['filter_id'] . "' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$current_category_id . "'";
} else {
// We show them all
$listing_sql = "select " . $select_column_list . " p.products_id, p.manufacturers_id, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) as final_price from ((" . TABLE_PRODUCTS_DESCRIPTION . " pd, " . TABLE_PRODUCTS . " p) left join " . TABLE_MANUFACTURERS . " m on p.manufacturers_id = m.manufacturers_id, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c) left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id where p.products_status = '1' and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '" . (int)$languages_id . "' and p2c.categories_id = '" . (int)$current_category_id . "'";
}
}
2. Now if you're getting "1054 - Unknown column 'p.products_id' in 'on clause'" then replace p.products_id = s.products_id with p2c.products_id = s.products_id EXCEPT on the line specified in the first step above.

Now open "advanced_search_results.php" from the same catalog directory in a text editor & do the following changes in it:

CHANGE FROM:
$from_str = "from " . TABLE_PRODUCTS . " p left join " . TABLE_MANUFACTURERS . " m using(manufacturers_id), " . TABLE_PRODUCTS_DESCRIPTION . " pd left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id, " . TABLE_CATEGORIES . " c, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c";
TO:
$from_str = "from ((" . TABLE_PRODUCTS . " p) left join " . TABLE_MANUFACTURERS . " m using(manufacturers_id), " . TABLE_PRODUCTS_DESCRIPTION . " pd) left join " . TABLE_SPECIALS . " s on p.products_id = s.products_id, " . TABLE_CATEGORIES . " c, " . TABLE_PRODUCTS_TO_CATEGORIES . " p2c";
**Ensure that this all comes on a single line..

You'd be all set now Enjoy..