Is the polarity of the jack adjustable via software? I've noticed that the Left/Right is reversed when listening directly from the headphone jack of the N900 - something that I've done very, very rarely so far due to the lack of a decent wired remote.

I just happened to crank up the N900 today while having a headphone directly plugged in, and noticed that the channels were reversed. Tried a track in QSpot, same. Via Bluetooth - fine. So I can only blame the jack.