On Mon, 5 Nov 2012, Chris J Arges wrote:

When an SB Arena USB headset is plugged in, it registers the volume
keys on the headset as a keyboard and continually sends events causing
issues with normal keyboard input. This quirk disables the volume keys.

I don't know how the device looks like, but wouldn't it make more sense to 
actually remap the bogus keys it's sending to produce KEY_VOLUMEUP and 
KEY_VOLUMEDOWN?

-- 
Jiri Kosina
SUSE Labs