Jumpy Twitchy Photos in Animation

I am using Flash MX v. 6.0 and have recently created my very first flash animation. My problem is that the photos are jumpy and twitchy when I put a tween on them. The object is supposed to appear getting closer whereas in fact I only enlarged the photo.
I have tried to place an action script on there as suggested by another forum:

_quality = “best”;

But, that doesn’t work. I’ve tried to up the fps and I’ve tried to alter the publish settings to ‘best’.

What am I doing wrong? I know this is a simple mistake but, would like someone to outright tell me exactly what I am doing wrong. Or if there is another way for creating this effect.
I appreciate all your help.
Here is the link to my website so you can see what the trouble is.

http://www.noria.com/conference/conferencesite/site.aspx?confID=1