ALL of the Diet Coke bottles we purchased last weekend at Wal-Mart smell musty/moldy - almost like per urine. Both the lid and the bottle smell this way. I've seen that this is a complaint from many areas recently. It's disgusting. Please respond with why it smells this way and if it's safe to continue to drink. We purchase 5-10 of these 6-packs monthly and need to know the cause.