I have the logitech x-540's plugged into my fujitsu laptop running vista, i connect them via the headphone jack, now they wont work, have connected the speakers up to the xbox 360 and they work, but when i plug them into the laptop they dont work any more..... they use to Yet when i unplug them the little speakers inbuilt in the laptop works, any idea how i can get them running on the computer again?