I am trying to copy five of the wedding DVDs to my computer. I could easily copy the first DVD. I cannot copy the other four discs. All the four discs struck in the middle. All the discs are clean and scratch-free. Then I noticed a weird pattern on the bottom of all the four discs. I have attached an image of that. But the first disc doesn't have this pattern. It is normal. Normally a burned disc will have the burned area and the free area. But these four discs are different. What are these? Does this pattern have anything to do with the copying?