TS3 sound problem

[phoenix1963]

I have a problem using TS3 with il2:CoD. When there are in game sounds, like the engine, my transmit on TS3 breaks up meaning I can't communicate with squad mates. When the game is quiet, they hear me.
I'm not using the Steam Talk, though I have mic volume up in it otherwise I'm mute.
I have a Creative X-Fi with the Win 7 64 bit drivers provided by the community (due to dismal support by Creative).
It seems like a source mixing problem to me, but I don't know how to fix it.

Grateful for any help,
56RAF_phoenix