just had a customer, who has been in some 3 times with a key problem, we copied her key and didn't work - can happen but on the second time coming back - I said to her any more problems please bring the original one.
this she has done and hey ho guess what it's a PATENTED yale key!
some local DONKEY has adjusted the copy key that makes it work.
cant some people look at the key and look for the word PATENTED it's right there on the key - this is cheap someone who cannot afford the extra 25p per key causes quite a few problems all.
So look - it's right there on the key!