Is your Dog a Picky Pooper?

I giggled when I read the thread's title. I had no idea that's how you call the behaviour!
My dog definitely is one. Before he does the deed, he wonders around, sniffing grass and just thinking.
I've heard about the research paper before, but it's hard for me to believe that dogs are truly pooping in order with Earth's magnetic field. More research is needed - though I sure wouldn't want to be one responsible for it!