I have 2 infra red keys (single button type with folding blade) and on both of these the red light comes on when I press the key button. However, only one of them will operate the central locking. This is despite brand new batteries being put into the (non working) key. I'm wondering whether it's just a case of programming the car and other (non working) key to make them "see" each other ? Alternatively, although the red light works in the other key, could it be that this key is not functioning somehow ? Anyone got any ideas please ?