Danny,
None of the keyboards I've ever had have had problems! You have had several. I think you have got a bad batch in the UK!! Every function works on my keyboards. All I can say is if there is a "lemon" keyboard, you must have it. I'm sorry for you!
Go to Utility page, find the button for Registration, then see if on any of the three pages, you could have possibly turned on or off the lock switches. I don't remember if this is even a possibilty in this mode, but check and see anyway. I don't have an X1 at home to look at it. This is just a thought.
George kaye