You can turn off camera animation in the properties panel for the camera you're using. Alternatively, use one camera while setting up the animation, and then switch to another for the render. Did you use IK on the arms? When you do that, Poser works out the "best" settings for the intermediate joints by itself, and it can get terribly confused. Or, it may just be that you inadvertently added some keyframes to the arms joints. If you go through the graphs for the various joints, you can probably see what went wrong. It may also help to try a different interpolation method.