I've been having this problem for some time now.
Every now and then, when I go to start my car...nothing happens. I turn it all the way, it clicks once, then the radio and A/C come on. It doesn't even ATTEMPT to start. When it does this, I jiggle the the the automatic thingy on park, and then it starts, but recently that hasn't worked.
I took it to the dealer once, and when it got there, it started up just fine! It's like the boy who cried wolf...
I have also replaced the battery.
If anyone has an idea of what it is, let me know.