Baldur's Gate: Backup Protection?

[phlegmhurl]

I tried making a backup of my original Baldur's Gate discs, they all copied fine with CloneCD and an HP CDR but when I tried playing the game with them, I get errors and have to put the original CD back in the drive. I tried the crack for XXXXX20 patch and it works at the start but later in the game it asks for the CD. My CDs are a bit scratched and might not have copied well but I'm thinking there's some sort of copy protection. Any ideas?