One of our key fobs has just refused to unlock the car. There were no prior symptoms, the other one still works fine and both are regularly in use. I have replaced the batteries and it will now unlock and lock the car OK but the car does not seem to recognise the key in the ignition. You do not get that click/buzz sound when you put the key in. I discovered that the car does recognise the key if I press the unlock button with it in the ignition and the car will then start OK, but I have to repeat this every time. Ideas please.