From the SA2 glitches guide (ignore that it says SA2B): Given GD-ROM's are non-rewritable, I don't see how that could possibly happen from just a Gameshark code. My guess is that the writer of that guide somehow mishandled the SA2 disc as he put it in the Dreamcast, and unwittingly damaged it in the process, resulting in the issues he encountered. But I'm still real curious; maybe there's something I'm missing? Does anyone else remember ever trying this, whether you saw it in the guide or not? If so, what happened, if anything? I feel like I might have made a thread or post about this here a long time ago, but I tried both Google and the forum's own search and can't find it, so I think I'm more likely misremembering. Sorry if I did!