Ripping difficulties: "National Parks: America's Best Idea"

I received this box set for Christmas and am wanting to put it onto my Apple TV. However, I cannot rip any of the discs using MacTheRipper 3, Make MKV or with VLC/Handbrake. VLC plays the discs just fine, so there's something going on here. Any ideas?

AnyDVD under Win 7 was able to decode the discs. Strange that MTR, MakeMKV and Handbrake could not.