Pajero Owners Club of South Africa

Hi , i have a lwb ,pajero,2001,3.2 did ,which ive had for about 18months or so. In that time i have put on a new battery and the starting motor has been refurbished. I am noticing now,usually first start in the morning if the radio was on when i turned the car off ,when i try to start it turns over as if there is no deisel,if i wait until the auto aerial is up it turns over and starts first time.
This problem doesnt seem to occur if the radio was switched off before the car was turned off
any suggestions ???