I know that God is not at all pleased when we choose wrong. God is even less pleased when our choices hurt others. Still, we have a choice. Finally, I got this out of nasty old hard drive. Okay, here is my theory on suffering.
Righteousness demands justice.
Our genetic material existed in Adam really and truly. I also suspect that we incurred some physiologic changes as a result of the fall. This idea of imputing guilt will come up again so keep it in mind. Of course this may not be the right answer at all but it is the best that I can do. I do not know which, if either, is the correct answer.