Playstation 2 ISO

I have an ISO backup of a Playstation 2 game. I used Nero Express (latest version), with a Lite-On 832S to write the image. I had massive problems with the ps2 trying hard to load the disc, but it either didn’t work at all, or was VERY slow.

When I burned the ISO using DVD Decrypter, the game played fine.

Is there some limitation I should know about with Nero and ISO for PS2?