Computer audio clicking noise in games, tv card ANNOYING HELP PLZ!!!

Hey guys i got the z-5500 system for xmas and my pc on board audio was shot DG31PR audio on just one side. So i went to best buy and got a cheap 25 dollar dynex 5.1 card with optical output... music sounds find but allright. Gaming and tv card have a veryvery annoying clicking. What is this whats going on??? I dont think its the sound system cuz i cant hear it on ps3 on music and i havent like blasted these speakers yet and they were brand new... I was talking to a guy on a game and he said it was a motherboard issue? Is this true? I had problems with the motherboard sound but i thought the sound card would fix that!. I wanted to change the sound card to a x fi the newer kind that is pci-e 1x but my biostars 8600 gts fan covers up the PCI-E 1X slot on my board ugh btw is there anything i can do about that? So does this sound like a motherboard issue or am i just doing something wrong or what please help