On this page:
http://www.pcgames.de/Far-Cry-3-PC-2175 ... z-1038695/ (which is in German, unfortunately), I found this:
"Far Cry 3 Issues: None Speech
In the sound card driver or in the Windows settings from 5.1 to stereo switch can solve the problem."
Seems like some people are having the speech issue when just playing, so that might be related.. the Logitech G35 is a USB headset, right? In that case, maybe try this:
http://forums.logitech.com/t5/Headphone ... d-p/383242
"Close the game, unplug the headphones. plug them back in, switch to stereo, then run the game.", and "I thought there was a switch on the side to turn off surround, no?"
Seems there's a little switch on the side here:
http://upload.wikimedia.org/wikipedia/c ... e_view.jpg ?
Sorry I can't be of more help, but I've really never, ever used surround sound in my life.
Edit: Found a review, and.. the switch on the right
here is apparently the "3D sound" toggle switch, which I would hope actually toggle surround-sound.
Review page
here.
So.. disconnect the headphones, flick that switch, reconnect them, try recording, and.. hope, I guess.