Well, I have a '10 (no disc) but mine also has a strange/odd and inconsistent behavior. I have nav up on display and park (off ignition and leave vehicle), come back and start the vehicle - sometimes the screen returns to Nav map as I left it and other times it returns to Menu display. When it returns to menu, Nav is highlighted so I click and then the nav map opens but not to the complete full view I had left it in. The left margin controls are activated so I have to scroll to the bottom one (scale) and click for the controls to move out and get the full complete screen view. As I said, other times I start up the vehicle and the Nav map opens full view (no left side controls activated) just as I had left it. I can find nothing different in my behavior which might be causing this random fluctuation and I cannot find a way to consistently reproduce the outcome.

Otherwise, my iDrive is pretty consistent. Occasionally I will be listening to a CD and iDrive shows "no disc" even tho it is playing.