How do i play back-up DVD's.

[qweasdzxc]

I own a Jap PS2, not sure what type, and it has a chip, not sure what chip. I live in Australia, so all the games I get are PAL. I have successfully burnt compact disc ps2 games using CDRwin, ASA patcher, and a CDRom burner, but whenever I try to burn DVD's it doesn't work. I'm relatively sure I rip them correctly and then apply the ASA patcher, but it still doesn't seem to be enough. Do i have to apply a DVD region patch, or something because i'm trying to play Australian DVD's on my Jap PS2? Any help would be appreciated. I hope i have supplied enought info.