DVDx 1.8a problem
 

Whenever I start up DVDx, I get a message saying about "auth.dll can't authticate drive disk may not be locked". Then I try to encode, it will stop at an arbitrary spot and tell me the drive is locked again, and to try and run the dvd through my dvd viewer software. Any suggestions on how I could fix this problem?

Maybe you don't have directx8.1. Maybe you are using wrong os, maybe the dvd is copy-protected. Try using smartripper, it will do the job, no matter what.