In the last month my 2005 Rover 25 has had problems starting. At times when I turn the ignition key there is a silence and then a two-tone warning sound starts. This has not happened first thing on cold mornings but when I have stopped after a short journey, and not every time then. Eventually it starts. I can see no mention of this sound in the handbook and my mechanic hasn`t heard of it before. Unfortunately when the car was serviced it started first time every time!