Problems booting dvd-r games on v1 ps2 (red screen) w/ dvd drive replaced though

Friend has been getting red screens (please insert playstation disc) with the ritek dvd-r games I gave him on his magic 3.1 v1 ps2. His ps2 does have a brand new dvd drive though. The games loaded fine in my messiah 2 pro v7 ps2 and a magic 3.1 v5 ps2. Any ideas on what could be causing these problems?

If cd backups work fine, try the alternate W point.

Do DVD originals boot OK? Sometimes with the Magic 3.X after the RSOD. Tap the reset and on the second try it uasally boots.