Shutterfly Is Freezing My Ipad 2

Shutterfly is having a July promotion for 101 free pictures. I selected 101 pictures and put them in my cart. At checkout, I tried multiple times to type in the promo code JULY101, but I never got past the "J" before the screen froze, beginning with the pop-up typewriter. I could not put the typewriter back down, neither could I get off that cart page. I couldn't even put the page down by pushing any buttons on the device. I tried shutting the pad off but couldn't even do that. I had to fiddle with two buttons simultaneously to finally get the pad to blank off. Every other app on my IPad is absolutely fine. Only when I try to get back to my Shutterfly cart do I have this problem. It is not allowing me to take advantage of this promotion without paralyzing my device. Please advise, and thank you.