I knew that the key hadn't gone all the way in as soon as I inserted it. I pulled it out and tried again. And again. What do you do then? I'm not the only one to have this problem though it's hard to find on internet because of the Bic Pen disaster. I have another Kryptonite lock (a U-Lock) and, like Unterhausen, have had it come close to not working a few times. But it always did eventually. Hopefully this one is just a lemon. I'll see what the Krytonite folks say.