My 15 plate Sports Nav did this, but it depended which version of software it was running. When I bought the car I could scroll through the stations using the steering wheel controls (as it should), but there was another problem with the system. When I selected a station the screen stayed on the list of stations, rather than going to the "now playing" screen. Therefore, for example, to start a phone call I had to choose the "now playing" screen to be able to use voice control. Anyway, long story short, the dealer updated the software to cure the problem (which it did), but it now wouldn't scroll through the stations. I had a further software update to cure that problem but it persisted. The dealers will fob you off with "yes Mazda are aware of the issue Sir and there's a new update coming out soon that'll fix it". Don't hold your breath.