Yesterday THIS happened two times:

Listening to music, suddenly sound quality drops. Only mid speaker playing. Go into options (bolero) to sort it out and am shocked - subwoofer slider, balance fader are gone from the screen! Imagine my face... 150km later stop to refill gas, after going back to car everything is OK. In the evening same situation, same solution - a few minites stop with keys off the car. Yestertday was a humid day, around 4•celsius and a bit of rain, guess it may be connected. Car has 4000km and 2 weeks.

The Canton Amplifier is connected to your Bolero system using fibre optic cables rather than standard copper wires (or so I am lead to believe). If they are damaged / small amount of dirt on the ends / maybe even humidity may interupt the signal to and from the amplifier, making the Bolero think it wasn't connected. Not sure how easy it is to access the cables to check connections but I'd say fingers crossed it was just a glitch and hope it wont happen again

I have it booked for checkout next tuesday and we'll see. And yes I believe it's optic.

My Bolero in the Superb does this sometimes, looses the fader controls or the looses the balance controls. Ignition off and back on again rectifies it.

 

Haven't bothered getting it to a dealer as there appears to be no rhyme or reason as to when it happens.