Well you can get bad pressings of any disc or there can be fingerprints or other not immediately obvious dirt etc that can interfere with the ripping process.
You could try cleaning the discs with soap and water, or for stubborn or greasy marks with a dab of isopropyl alcohol or methylated spirits on a lint free cloth.
These are safe for use on optical discs as they're mild and evaporate quickly but don't use any other solvents as you could damage the disc.
Are there any obvious defects on either disc?
You may need to hold the disc near a light and reflect the light on the surface at the correct angle to be able to see it.
Another trick to spot defects in the reflective layer is to look at the disc with a bright light behind it and look for any pinholes or irregularities that let through more light.
If it's happening with multiple discs in multiple computers then I'd suspect a damaged or dirty disc.
If you're lucky someone else here might have one of those discs and be able to comment further.