Unusual fault?

BMW E39 528i. After a cold night on drive. Unlocked the car, put the key in to start car. Instrument display dead. Nothing showing at all. Started car. No fuel, rev or mileage reading. Drove about 10 miles with nothing showing, Speedo, rev counter, temp, etc etc all dead. Parked up and locked the car to get car park ticket. Came back, unlocked car, and tried the key in the ign lock. Display lit up as normal. Did a bit of shopping, and display was still OK when I came to drive home, and remained so all the way home. I assume the problem has cured iitself. Unusual, or not uncommon with BMW instrument panels? Mike.