It has happened to every coupon diva at least once. You have carefully planned out the specials, checked the coupons expiration dates, plotted the fastest course through both traffic and the store, filled up the cart, gotten any rainchecks, painstakingly stacked all of the items on the belt and have the appropriate coupon in hand when suddenly… the cashier says something like, we only allow double coupons on three of the same item or there is a limit of 10, or we can only give you up to $XX amount for each transaction, or something like there needs to be another person because it is only five allowed per customer.
There is really only one way to make sure that does not happen when you are couponing. Call the store, ask them about their policy or any policy changes and write down the name of the manager (yes, get it from a manager) you spoke to so that if something comes up it can be over ridden.
It might seem like a bit of a hassle, but it is nothing compared to spending an hour or three at the checkout counter trying to figure out how to get your haul for what you planned to spend. If you are a coupon mom with kids in tow, chances are, that is not how you want to spend your day. So, make it part of your before trip planning.