Fix the position of an mc loader

back with another question
I have a row of thumbnails with a simple rollover effect.( I load a swf for each thumbnail preview)
with the following code from the kirupa tuto.
[COLOR=blue]on (rollOver) {
loadMovie (“mesimages/im1.swf”, “dropzone”);
}[/COLOR]
it works fine BUT : my swfs are appearing in a crazy position even if I created an mc as indicated in the tuto…
Do have I to settle my self the position of my previews in the code ?
Thanks thanks thanks