You can use expired coupons at Bed, Bath, and Beyond, but not Buy Buy Baby. I tried to have them waive free shipping once and they wouldn't in conjuction with the coupon (they would do one but not the other). However, I returned a baby item from our registry to Buy Buy Baby and re-purchased it in another size, and they allowed both the coupon and the free shipping, so I suppose it depends on who you speak with.
Mom to a spirited, red-headed, former 28-weeker 10/2009 and a more mellow monkey 12/2013.