I am posting to clarify things a bit: DVDRebuilder does not crop the edges, in order to obtain 1.77:1 images. I've tried this procedure mentioned earlier with several "original" non-anamorphic DVDs of varying ratios (from "Nixon" and "Life is Beautiful" to Kurosawa's "High and Low" and others, including "Blade Runner"), and in none of the cases did I lose the sides of the image, as a result of the "crop/blow-up" process. I haven't seen the "2 black bars of diferent shades" phenomenon, either. I'm just happy it works.

dark_jedi, I hope you're sending Rikter copies of the materials on the second Criterion LD...?