Burnt ps2 dvd works then stops and then next day works again

i burnt a ps2 game( dvd decrypter, 2x write speed, sony dvd-r).
and it was working fine when i closed my ps2 and tried it again it wasnt working no more(playstaion 2 logo comes then a complete blank screen).
the next day i tried it started working when i took my memory card out of the card slot.
then i closed my ps2, now it isnt working even with the memory card out.(i have an original rachet and clank 3 and thats working perfectly, i also have other burnt ps2 games that have a sliver backside, they seem to work but not completely as they are scratched).
is it a problem with the laser or the modchip?
i have a scph-75004(V14)
there are two more things.
so what cud be the problem?
i have also added a cd label(paper) to my dvd, cud that prevent it from functioning properly?
pls help, getting frustrated no wanting to spend all my money on rebuilding the entire thing:sad: