Here are my findings whilst trying to backup C&C Renegade. I post them in case they may help someone work out why they are getting coasters when others are having no problem. As FutureProof has documented this is a tricky beast to copy, and the results are not always predictable.

First let me explain the why;

A friend of mine who is at college has a burner that will not duplicate SD2.51, so when he's home he comes round to me and I duplicate his games with my LTR-40125S. He then takes the backups to college and leaves the originals at his parents place.

So here's what happened.....

He got his copy of Renegade and came round to see me, I copied it and he went back to college and told me the game didn't run from the copy, he then downloaded the No CD fix and was happy.

I got my copy last week and did my own backup which worked fine first time, every time

We both have pretty similar PC's - both Dell, both with NEC-5700 DVD's both with 1.05 firmware. I used Clone CD 3.4.4.1 each time. My friend came back to see me this weekend past and, at my request, brought the old disks and some new blanks.

In my PC I would get about a 50% failure to authenticate the disk with his copy - burned on 'Memorex' branded disks [manufacturer unknown]. My copy was burned to 'Mr Data' blanks [again manufacturer unknown] and authenticated everytime.

I then burned another copy of Disk Two onto the Memorex blank he brought with him, and it worked every time.

So what did I do different second time;

Firstly; I read and wrote in the Lite-On, before I read in the NEC and wrote in the Lite-On.

Secondly; before the burn I updated the firmware of the Lite-On from ZS08 to ZS0A

Thirdly; I reduced the burn speed from 24x to 16x

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So the moral of the story, well I'm not really sure, there is nothing here that I'd call conclusive. Others have posted about the burn speed being significant and my findings echo that, slower is more likely to give a working copy. Perhaps the hardware error correction of the Lite-On is better than that of the NEC and maybe the Firmware update has made the copy 'better' in some way.

If anyone can explain this then feel free I'd love to get to the bottom of this.

I was reading a post by OC-Freak about the burn speed shift of some drives and what happens at the point of the speed shift
So how's this for a theory;


So maybe the speed shift does induce an error on the disk, which is picked up by the SD2.51 check and causes the problems some people have spoken about with SD2.51 killer burners not correctly backing the disk up. I know that pretty much every backup I do at Max speed fails the copy protection check one time in about 5, but burnt at a constant speed [I chose 16x as a test] the backup works each time every time. That has been proved with Max Payne and C&C Renegade so far.

Interesting theory but I don't think Z-CLV recording introduces an error to the disc. When switching zones the gap is about 1 micron and too small to be noticeable. Then what is the reason for your results? Well I don't know. Maybe, just maybe, the switching of the write speed occurs when writing the 'weak sectors'. This confirms your theory but I have no idea if this is the case so I (we) can be totally wrong here. More tests would be welcome people!