Anti-Modchip PlayStation 1 games on PlayStation 2 consoles

[helakustorm]

I've read on every site that Modbo modchips will support those games only on V9 through V16 consoles.
On the rest of them V1-V8 and V17-18 they will only work if you patch them.

Someone knows why?

And another question: if you play an anti-modchip NTSC PS1 game on a PAL PS2 console the game will work or the game must be from the same region as the console?

Thanks!