One of my companies employees has a powerbook which he has tried hooking up to an external monitor using the DVI cable. The monitor make and model is Acer AL2032WD he can hook it up and see the picture but there are black bands arount he top and sides of the image so its not filling up the whole screen. I am basically illiterate when it comes to Macs so I was wondering if anyone on here could give me some basic steps to try to get the image to become full size.