Could just be a corrupted CD. Try to burn another one. If that fails, try another live distro. I have similar problems with my CD drive that it fails to boot the Ubuntu Live CD (fails right after uncompressing the kernel), but it's fine with the alternative install CD, and works OK with knoppix.
I suspect my drive to be either somewhat broken, or perhaps with a weird (NEC) chipset which doesn't work well with the drivers in some kernels / under some conditions.