Why is it everytime I'm trying to back up my .iso (dvd image) in DVD DeCRYPTOR it always writes in .7x, even though I change the write setting speed to 4x. I have a maddog external 16x burner, and i'm using fuji film 8x dvd+r. I set the write to 4x, but when it starts writing it writes at .7x. It's weird. Any suggestions.