no ATC voices - soundcard problem?

Plzzz...can anyone help me, in FSX I have all noises ( engine, airplane, weather noise etc), except ATC noise, I cant hear any ATC messeges, there is ATC text, but no voice, sometimes it says one word 10 times! I have SP1 and SP2 also!I have tried 3 times reinstal FSX, I've tried reinstall sound card, I've tried to change fsx.cgf file, in FSX I put audio and voice sound device similar, but no result.....I have SoundMax as default soundcard, in FSX audio column shows that there is default primelary device, in Voice column shows just default device, I changed both to show SoundMax device, but no voices!I heard that its because FSX voice and sound need different sound drivers, to hear seperatly in speakers and headphones, I dont know....Can anyone tell me what to do???I have 5,2 GHZ Athlon, 2 GB RAM, 512 MB GF, maybe my graphcard eats resources from sound card.....what should do?maybe I need to change something in cfg file to show just one sound device for voice and sound?