I bought some lactose free (and fat free) milk a few days ago. I've drank it a couple times, and it seems to give me a fair amount of gas. Does this happen to anyone else?I also noticed that in the list of ingredients, it lists "lactase enzyme". Of course that's the enzyme that lets you digest lactose. But if the milk is lactose free, then why do they need to add lactase enzyme? Is the milk really not lactose free?