The credit card hack Target suffered at the start of the holiday shopping season will go down as its biggest blow of Christmas 2013 ... but it won't enter the history books as the only shopping mishap. CNNMoney reports that some of the Target gift cards purchased over the holiday period weren't "fully activated"—meaning shoppers are experiencing a fresh headache in the checkout line. Target says the error is a very tiny one, affecting "less than .1%" of all gift cards over the holiday season. Those with problem cards will be able to use them, but they'll need to go to Guest Services or call 800-544-2943 in order to do so. (More Target stories.)