From my code posted before:

In admin/includes/modules/product/collect_info.php around line 41 look for this line
PHP Code:
'master_categories_id' => '' 

and change it to
PHP Code:
'master_categories_id' => '',
'facebook_add' => '' 

You have left out the comma after 'master_categories_id' => ''

And again, you left out the comma here in update_products:
PHP Code:
'products_price_sorter' => zen_db_prepare_input($_POST['products_price_sorter']),
'facebook_add' => zen_db_prepare_input($_POST['facebook_add']) 
When changing code you should just replace the entire snippet instead of trying to insert only the new code so you don't forget to miss the little things like commas.