Why do the ps2 games i burn not work?

[Utkarsh]

Hey guys
i got a ps2 recently .. a PAL one..
i downloaded a few games such as Burnout, WWF Smackdown 3, Splashdown etc

when i burn these games, i find that they dont even boot... they hang at the loading screen of the game and i hear loud clicking sounds from the cd.. some even give me a black screen of death

i use a HP 9100i with CDRWIN in default settings at various speeds on Samsung media
i have a neokey usb mod and the Memory Manager 16 to boot the games..

I would really appreciate if someone could help me out
Peace