You have to explain your procedures. Blanket statements serve noone. Provide screenshots and the necessary info.
The procedure goes like this:
• Create a position keyframe for layer
• At new time (say 24frs) move layer in comp window to create new position keyframe.
• Repeat as necessary to create an animation (of a bee flying in this instance).
The problem as I mentioned is that on some occasions AE creates bezier keyframes and then switches to linear ones on the same motion path and I can't figure out why it would do this apparently at random.