In the past I had no problems burning ISOs for my PS2. Though now, these days the DVDs I burn don't work correctly or even work at all on my PS2.
Before you say anything yes, I have the required tools and stuff to play Burnt ISOs and have been doing it for nearly two years now.
Here are the programs I use.
Nero
DVD Decrypter
Img Burn
Perhaps if someone told me their way of burning it, maybe I could find what went wrong in the burning.