Not really like you but I heard some friends alking about several movie and when I saw some shots on WTM I think "that could be that one" and it often works
I solved 'Tenacious D in The Pick of Destiny' because I saw the Kickapoo music video :p But I don't read books normally, so I don't think I'll ever solve a still that way :D
I solved some shots of Immortel (ad vitam) only by knowing the comic it is based on (la trilogie nikopol). I think it helped that the director of the movie actually was the author of the comic (Enki Bilal).
Nope, I don't think I have solved any shot by knowing the book. But I solved one shot by knowing a Simpsons-Episode which featured a key element of the still ^^