Audigy: Front channels coming through _one_ speaker.

I have a very weird problem. I have an Audigy card
with Four Point Surround (FPS1600) speakers. Yesterday
I noticed the sound didn't seem normal; when I ran
the speaker test, both the front left _and_ front right
channel came out of the front left speaker, and nothing
comes from the front right speaker. The rear speakers
work as normal. Swapping the connections, the sound came
from the front right speaker, so the speaker wasn't the problem.

I've tried uninstalling Audigy (which crashed my
machine, but that's a side point), then tried
uninstalling and reinstalling all the accompanying
software. I also ran the Diagnostics tool and
reset all values to the default. None of this has
made a difference. I've tried setting my number
of speakers to both 4 and to 5.1.

Does anyone know how two channels might possibly be
output to _one_ speaker?

Thanks,

P.

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