The first issue as AutoBLogged pointed out is that you’ve incorrectly referenced _FILE_ and not __FILE__ in the first activation hook.
There’s a possible secondary problem, and i say possible because i’ve never had to use the activation or deactivation hooks extensively myself, and that’s with calling register_activation_hook twice, once toward the top of the script, and once toward the bottom.
I’d assume(and i could be wrong here) that you can’t create two seperate activation hooks for a single file. The solution should be simple though, take the code from both functions and move it into one, so you only need one call to register_activation_hook.