Ok, I've done a fresh install of Windows XP SP2, however, when i burn a dvd rom in Nero, the buffer level bar at the very bottom of the screen keeps fluctuating from full to empty, it just keeps going left and right, left and right... and also, it's taking a lot longer to burn (usually 20 mins at 4X) but right now it's been 30 mins and it's only 84% done... I'm scared, what's going on?