When you clikc on a planet or any structure and you go to one of the submenu buttons, to say build a ship. Then you click on another planet you end up at the same menu structure. If you click on a planet then a submenu to build something like a ship, click in some blank space, then click on a planet, it reverts back to the base menu, where you see your planet, your ship factories your tactical options and the like.

I don't know if this is supposed to be this way, but I find it a little annoying, to be at the same menu/submenu level if you click on planet after planet you own.