The point is if you let a "friend" use your browser for short time he/she can just read all the passwords that are saved.
Thats an usual thing and no one logs off just to let a friend watch an website.
Interesting, I always need to enter my computer password to see my saved passwords. Well, it does not ask again for some minutes, but then passwords will be locked again.
If you restart Opera, does it ask for computer password afterwards (when accessing passwords)?
(I assume you have computer password set.)