XC60 problem with sound system and screen

I have just bought a new XC60 D5. What a wonderful car. Need some advice though. Every now and then, my sound system goes into a "funny" mode where the display gets stuck on a foreign "radio only" mode. In this mode the telephone, DVD, park assist, My Car buttons do not work at all. This is very strange and also intermittent - it has happened three times, and later when I start the car all is normal again. Even the on/off button on the radio then does not seem to work. Any advice ? Am I doing something wrong ? Is this a software problem ?

Thanks

Chris