> You find yourself in a locked room with no windows, and no memory of how you got there....
> What's wrong with the reasoning here?
This is also in response to your explanation to me of copying etc. in your last post to "Many pasts?..."
I think there is too much we don't know about quantum behavior vs. macro-matter (e.g. human bodies) behavior to say that copying, and subsequent diverging histories, is not like dividing by zero. I think that even if it were possible to copy a body (i.e. exactly) and have more than one copy at the same time, for the purposes of your thought-experiment why wouldn't it be the equivalent of quantum entanglement where you really have the equivalent of just the original? This is where I think the reasoning in your puzzle is flawed. Having 10^100+1 identical bodies is equivalent to having one body, so it makes it a 50/50 chance. Until the information is actually revealed, it would be just like the copying didn't happen, therefore there is no way to tell which state (copied or not copied) is currently in effect. Even though this may not be an appealing option, I believe that copying, if possible, wou! ldn't change anything having to do with identity (it doesn't "add to the measure"). Like Einstein said, insanity is doing the same thing over and over again and expecting a different result.
In addition, even if copying a body with two subsequent diverging histories were possible, why wouldn't this become just like two different people? Who cares if there are disputes? That's nothing new. What does that have to do with consiousness? I don't believe that identity is dependent on consciousness.