Headset/Soundcard annoying problem

I have some weird problems with my headset lately, when i listen to music one of the speakers (5.1, Front left/right ) simply just shuts off there is no sound coming from it and then like 5 sec later it pops up again and then 10 sec later it shuts off again and somethimes the sound/speaker doens't come back on but i have to reset my PC or something like that. At first i though it was mayby bad headset so i bought another one (same one) and it worked just fine but then 2 weeks later BAM! same problem. I asked a couple of friends of mine what could be the problem and they said its mayby my soundcard or something or my power or USB or something like that.

I later though well if its my soundcard i'm not gonna plug my headset in it anymore till i can buy another one so i plugged my headset to my onboard audio and... yep same shit happend :S. I have all my Realtek and Creative Soundblaster drivers up to date and my PC is pretty clean no virus or anything like that. I must say when i listed to music i really turn up the volume like if my headset's MAX volume is 10 i set it like at 6-7 could it be that the volume is killing my headset? Anyway i hope that somebody can help me sorry for my crappy english. My specs:

Headset: Speedlink Medusa 5.1 Progamer headset (jack cables)
Soundcard: Sound Blaster X-Fi XtremeGamer Fatal1ty Professional Series

Anyone?

Try giggling the jack in the hole if this causes static or the sound to cut in and out then the contacts on the sound card are loose