I would imagine that this is the new strains of copy protection coming into play...
Ok, you will have to disable autoplay etc.. so that the DVD does not start up - as they all rely on a small low level driver that causes the problems.
If you can disable the autoplay function and/or hold down the shift key after insertion - you may get better results with the Decryption.
My friend is having similar probs with the latest DVD Decryptor - he tried my older version and it works fine!!!
Try getting hold of an older version of DVD Decryptor - if you cant mail me and I'll put on my FTP for you!