burning PS2 games is not as simple as burning ordinary DVDs. Some games need codes integrated into the copying/decrypting process. others have special methods as traditional PS2 back-upping don't work at all. with your comment about using alcohol, and dvd decrypter, I'm sure that you are already familiar with this.

having said this, you are also right that the quality of the dvd-r may be responsible for the discs not playing. I have tried burning downloaded games before and some dvd-rs don't read well on my PS2 while others do.

A site that might help is forum.afterdawn.com. lots of useful info there on this topic.