CD Head Unit Problem????

[spudsnall]

Got in the car today -3 degrees and cd worked ok. I parked up and went back to the car and started it up. The CD worked ok but I had no track list in computer trip window and the steering wheel volume and cd change control would not work. The other thing was a could not turn the head unit off using the power button. The cd carried on playing when I turned ignition off and removed the keys. Then I left it for 10 mins everything was back on but even with the keys out. Can anyone shed any light on this please.