Faulty 156 GTA BOSE head unit?

[viper_larry]

Before I call the dealers, thought I'd ask your advice here.

My BOSE head unit when first switched on only plays out the left side. If I press the SRC button a few times to switch between radio and CD, it works from both sides. Can't be a loose wire to the speakers, but any other ideas?

Could it be a faulty unit that I could get repalced under warranty? Gets rather irritating fiddling about for a few minutes each journey.