problem importing DVDs

[aris]

hello all,
i use VS9 (downloadable upgrade from VS8)
i am trying to import chapters of DVDs recorded by me, all with the same software (DECRYPTER - CLONE) and the same recorder (TEAC DL).
in most of them i did not had any problems, perfect and quick.
in some of them (about 2 out of 5) the preview screen was BLACK, and i didnt find any possible reason. i tried changing capturing plugins, but nothing better.
those DVDs work fine on PC and desktop too. actually as i told you they are made with the completely same way with the others that work.
i have installed the update (patch 5in1, 8-11-05)
i would appreciate any help.
thanks