Such CRC errors are usually attributed to dirty/scratched cds. There could well be a nasty scratch on the bottom of your disk that just can't be read by the readers.
You could try cleaning it with a soft lint free cloth from the inside out (not circularly). Or if there is a real nasty scratch you could use a tiny amount of toothpaste on the cd.
Also, try reading it in Clone CD with Fast Error Skip enabled, it should give you an idea of how much of the disk is affected. And maybe set read retries to max and read speed to very slow.