Actually that's not quite true, the Solider says that there are serious questions about the issue, and that Obama *might* not really be President, not that he is not. Big difference, he's just asking for clarification. It would have been nice if the case could be settled prior to the guy's reporting date. That way, if he loses, or BHO is proven to actually be a NBC, although his career might be ruined, at least he would not have violated any law or regulation and could retire in peace, after this deployment of course.
The Major is seeking a temporary restraining order in a federal court.
The Major has also clearly stated in his brief that he is "ready, willing, and able" to deploy.
At this point in time, I do not see how that places him in any legal jeopardy.