Every Starforce protected game has the same key.
Your error is caused by a bad mds file. You can get one on
www.copybase.ch
By the way your method is totally wrong. You can't run POP with SF nightmare. You need at least SFcure or you unplugg your DVD-devices and mount your image in DaemonTools 4.
If you have a VIA chipset on your motherboard than have a look at the
protection-forum.