what is an MDS file? i copied need for speed undergroudn 2 and i created an ISO 4GB file. it also created a MDS 5KB File. what is the MDS file and how do i write it to the same DVD-R using dvd decrypter as wel as writing the ISO file? do i need the MDS file as well as the ISO because i wrote the ISO to a DVD-R and tried to play it on my chipped PS" bu it would not work. what has gone wrong?