Sound coming out of wrong speakers

[Mr_Blastman]

So this is strange...

I am using Zandronum 3.0
I have Klipsch 4.1 speaker system
Windows 7 64-bit
Creative X-Fi card

When I play Brutal Doom 1.9 I notice enemy grunt shotgun sounds _only_ coming out of my right rear speaker when they are behind me. If they are to my left, I hear nothing out of the left rear. This also happens with exploding barrels, even if they are in front of me - back right rear speaker. Never the left. All other effects come out of the correct speakers, be it regular guns, doors, shell casing, etc.

What gives? Any ideas on how to fix?


edit: Also, what audio codec does Zandronum use for sound effect output?