potrebbe essere un errore di copia incolla o chissa che.... prova:

codice:
select count(p.products_id) as total 
from products_description pd, products p, products_to_categories p2c
left join manufacturers m on p.manufacturers_id = m.manufacturers_id
left join 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 = '4' 
and p2c.categories_id = '63'