Now, you may just download the latest version 2.0.7 of Ideal DVD to
Avi Converter from http://www.idealdvdcopy.com/dvd-to-avi.htm and
install it. Then have a try. When ripping, ensure your computer is
connected to internet and don't run other decrypters in the
background.
If you still can't rip"Thor" with this version, that mostly means your
DVD is another edition they haven't met, just keep the DVD in your DVD
drive, click "File"->"Export ifo files" menu, save the exported file
and send the .iba file to their support team , they'll analyze it and
fix it within one day.