I was really asking to elimate the headset, seems you are having some issues with them as it is. Could very well be the soundcard but I was trying to elimate the headset first, then we can delve deeper if it is the sound card.
Edit: I have read as well it may not just be the audio drivers you need to updatee, might want to check to see if there is a bios update as well for your motherboard. but lets start simple with the headset first.
Edit2: Another thought, if I remember you saying the headset has a volume of it's own, you might play with the volumes on the windows side and the headset side as you may have some clipping occuring between the two volume sets.