ps1 copying

[welsh warrior]

Hi,
Can someone tell me where i can get the info on how to copy ps1 using clone cd.I have tried 2 games using nero and it wont copy them,keeps coming up with errors even though they are not protected.Others i have copied no problem but cant copy (alien trilogy and colin macrae).
I have a plextor 8432t which i think is compatiable as i have used it to copy pc games.
Your help would be grateful

welsh warrior