I've used 3 coupons on three different items on the same transaction. Haven't done it with this year's version of the coupon, but it wasn't a problem last year.
some cashiers have let me use multiple coupons on the same transaction, while others tell me they'll ring me up on multiple transactions...which makes me feel really bad if customers are behind me...i try to only go when the store isn't crazy busy, which it usually is