Problem updating NAVI DVD

[Norse]

Hi
I tried to insert a v.10 Navi DVD for comand APS in my car today, but about 30 seconds after the update display came up the display read "SEVERE ERROR IN NAVIGATION UNIT" , and the update process halted. After removing the DVD and reinserting the old disc and waiting a few minutes everything seemed ok.
Anyone have any idea what happened?

 

[Norse]

I tried two more times, and for some reason it was suddenly ok.