I agree about the food quality. Make sure he is on a high quality kibble, it may be a number of things, but I've heard of tons of dogs stopping this after being switched to a more nutritious diet. Same with dogs who eat dirt or plants and whatnot, it can often be linked to them knowing they're missing out on something.

I hope you can solve this, anyway! I would definitely rather try a higher quality food than start adding stuff to his kibble right away. Thank GOD Fozzie doesn't do that... I really pity those of you who do have poop-eaters, their breath must be very interesting. =P