[jdiwnab]

One mistake I make is that I move an object while the animate, or auto key (depending on the version), button is on when I don't want to animate it. If you select an object, you can see the 'keys' on the time slider. By right clicking on them, you can see what they are changing. You can move them and delete them as you want. Still not working right, there should be an animation curve editor tab near the time slider. Open that and select you part from the long list. There should be X,Y,Z and rotation lines. Select the offending movement and adjust the curve accordingly. Though, getting it right this way is hard. Try the other ways first.