Really, they do. Do your guests a favor and register somewhere else.
My friend had her baby shower this weekend. I went to 2 Targets in the area, and those kiosks with registries didn't work. So one Target employee said "If you have a smart phone, you can find the registry online". Well, duh, Einstein, and then how will the items come off the registry?
So I went back home and printed it out, hoping nobody buys stuff in the meantime. After about 4 hours after the purchase, the items were still on the registry. So I talked to someone in their registry help department who barely spoke English and asked me 18 million security questions, and things were finally marked as purchased. Yay.
FWIW, no, I did not bitch to my pregnant friend.