hi, i have a soundblaster X-Fi sound card and Logitech Z5500 speaker system, in some how, when I do the test of X-Fi, the to rear speakers make noise when signal is only for one of them (rear left speaker on monitor both make sound, rear rite speaker on monitor both make sounds) And then I checked the sound tester in the speaker controll panel, every speaker seems working fine, rear speakers dont make noise at the same time, is anyone have a solution for this?