Xfi Buzzing Noise?

I have an Xfi soundcard (Xtreme Gamer)and I have a lot of trouble with a bleeding noise through either my headphones or speakers!!!.. Yes Im a Musician and Ive tried connecting to the white plug In the back with 2 different mics and ok I dont get the buzz, but really low sound and have to hold Mic close even If I raise the volume. Still when I plug into the front/side panel I plug In my microphone, I speak a little and boom, that really horrid (Ear Bleeding Noise) happens to re-appear no matter of the tone or volume of my voice!, If I lower the mic volume from within the Gamer mode/Audio creation mode everything seems to be fine, but still cant hear much comming from the speakers, ive tried upgrading drivers/bios, move soundcard to new PCI slot, no success, can anyone tell me the sollution to all my woes... Why Is It buzzing like this?, would appreaciate any knowledgeable person to answer this, thank you all!.