Thats it. I have confirmed that this work.

1 - Boot dvdregionx
2- On region screen, swap with cog method the dvdregionx cd with gs2.1 backup. Then will boot
3- Then will go to gs2.1 screen. Go to options and click in reset hardware, then will go back to main screen few seconds later.
4- Press eject and put a large original DVD game on it, then close. DMC demo is a good choice.
5- Go to gameshark codes, choose any game then the cheat screen will appear. Desmark one cheat, then mark back. Press circle to go back to main screen.
6- Click on start game, then click without codes. Will appear a message to confirme with x. Wait.
7- Prepare to make the knife/swap. Press x then you will hear the DVD stop spinning, then make the swap with dvdr while the "upating list code" screen is showing. Do you have +- 7 s. Is done

What do you need to do this:
- dvd regionx
- gameshark 2.1 backup. Obs: don't need the dongle
- Original Game DVD with large TOC
- Your game backup disc

I have a ps2 scph30001 v1 US machine

Thats it. Sorry by my english, because I am brazilian.

I have tested this with gameshark 1.9 backup but when I boot appear a hardware not detect screen and I can't go to the main menu screen of gameshark. Maybe because that need the gameshark dongle.
So I am searching for the gameshark 2.0, to do the dave mirra trick with all that. If someone have it.. email me at eduabrao@yahoo.com.br

The gameshark 2.1 copy you can find at http://gamezone3k.4-all.org/

why do you need to boot the gameshark?

^ as it is a copy so wont direct boot, you can boot cd games with the dvd region x

this is just the double swop thing with the knife method involved

but quite a clever method

Quite long & not that cheap really, but another alternative.