My 04 LS430 with Nav. and Mark Levinson sound system after I start the car and press the radio on button the radio does not start until the radio has been on for 4 to 5 minutes after that I can turn it on and off like regular while car is in use until the car has been sitting for a while and it goes back to the 4 to 5 min wait again. Anyone know what is going on ? Thank you..