Simple Image Tween Problem

Why oh why does an image insist on darting off to another part of the screen when all you've down is lay down a simple fade-in tween?

How can I prevent this? The image moves to the top right-hand side of the screen mid-tween as if it's posessed, when all I have done is asked it to fade in.

perhaps post the .fla it sometimes will depend how you set up the tween..
try tweening from 99% alpha to 1% alpha rather than 100% to 0%