some copies won't work

[1sparky1]

Try using cdr-win. Burn it to an image file and then onto your blank disc. For some reason certain games will work initially. But after a few plays won't get recognized as a disk on your ps console.
Clone-cd seems to be great at first but more elaborate games seem to fail after a disk to disk copy. Patching also seems to help, whether it needs one or not... I seem to get better copies after applying the games patch.