try resetting CMOS (turn off your computer and take out the small battery on your motherboard, after you unplugged the PC from the wall socket. Let the pc sit for 5-10 mins), if that doesn't work it's probably hardware related. I'm not sure what could cause this problem though.
Volar, did you fix your problem? I have the exact same thing with my computer, really hope you did it cus I'v serch google dry fo this, no luck yet :P best regards.