Watch closely in the scene where the Millenium Falcon is attempting to escape from the Star Destroyers by entering the asteroid field. When Han comes into the cockpit and takes over the controls, Princess Leia is sitting behind him and C3-P0 is sitting behing Chewbacca. There are several shots of the four in these positions. There is a grouping of several shots showing the Falcon avoiding various asteroidal bodies, then, when the shot switches back to the cockpit, the Princess is now sitting behind Chewbacca and C3-P0 is behind Han. Maybe they switched seats to get a better look at the action, who knows?