2000 740il Blank Nav Screen

The nav screen on my 740il showed black. The time, date, and year functions showed and were operational. I then stopped the car and re-started and the screen came back up and displayed normally. Any ideas on what could have caused this and is there a problem coming up down the road? Thanks for any input.

have you tired disconnecting the battery waiting and letting the computer reset. that might work.. if not your screen might be going out