This morning on the way to work, a problem just ocured on my Business Radio RDS display. After I started off, I noticed that the display gone off. To have the display on again I had to switch de radio off and on. Display remains on for about some seconds, I think 20 seconds (this is a fixed period). The same occurs to clock, but when I press the clock button it goes on and after 20 sec aprox. goes off again. This happens separatly from radio / clock. Can you tell me what to do ? Car: BMW 525TDS / Diesel - 1997 (E39) PORTUGAL