I'll second that. Make the image file first, then burn from the image file.

The problem with a disc-to-disc burn is that they have to be fairly synchronized with both the reading and burning process. There's far less room for error when copying discs for DC games as opposed to making a music cd or the like. If your dvd drive reads the backup copy any slower than the burner is writing - at any point during the copy process - it's going to produce an error.

Bottom line, it's always worth the extra time to make an image file first (which doesn't take that long, anyway).