I had four internet printed coupons-manufacturers' and not expired...my Kroger cashier tried to scan them but they wouldn't. She said she tried to put them in manually but it wouldn't accept them. She said something about if the ink printed too dark or too light it sometimes wouldn't take them. They were four .50 coupons for Betty Crocker muffin mix, on sale as well. I would NOT have bought them if I'd known the coupon wouldn't work, but she'd already scanned & bagged them all so I felt too bad to ask her to take them back off (I had 10!). I'm sure this has happened to others....what can or should you do about it??