As Alchy found out is usually IS the DVD drive. I have a Sammy Kreon drive that has lots of issues reading scratched/scuffed/blemished discs all the time. Pop it into my LG DVD burner and it'll rip at 12x without a single hiccup. Different discs, different drives. All seem to have preferences.
My drive was dying. I am on my way to pick up a new drive with excellent error correction. Sony AD-7260S
I use Alcohol 120%. I paid £30 or whatever it was in 2003 and never looked back since. It will rip just about anything provided you have a decent reader.