y wont my backups work?but my old 1s do?

[hiddendragon]

Hi everyone,hope you can help with some probs im having with my psx backups.
My chipped playstation plays my old backups fine,these were games that i got copied a long time ago,now that ive got children who like to use my cds as frisbees!i would like to backup my better games(bomberman world,capcom generations,final fantasy IX etc).
Everytime i copy a game and then try and load it up on my ps the disc wouldnt even spin,ive tinkered with the little screw to adjust the lens and now my copies get as far as the white playstation logo and then goes into the memory + audio screen.
So far ive tried using nero,cdrwin,clone cd all at different speeds and settings but still no luck! ive used memorex and now tdk cdrw disks,tried the playstation on its side and upside down,still no go.I have compared the data on my copy to the original and there is no difference in content,am i missing something apart from my insanity?
Hope someone can help,thanks in advance.