You made me find out how to tell the difference between the two. After I read your post, my curiosity was peaked. I pulled out a few titles that I knew were single and dual layered from different studios and looked for differences. Well, on the bottom of the discs there is an ID ring near the center. You will see BVSS or BVDL. BVSS is the single layer marker and of course the BVDL is the dual layer marker.
Now, everyone will be looking at the bottom of their discs...lol!
