really bad!!

What I am trying to do really isn't all that hard. I am 7 days into my flash adventure (First one). I picked up a book to get the concept down right by Savvy that covers the program.

Anyway, just let it be known that I am a newbie .

Now here's my problem, i have a movie which is gonna be a website. I am making a nav bar in photoshop but I wanted some interaction with it. So i have an image that I put into my "movie clip" frame 1. Then I made a keyframe on 15. Now I have the whole timeline (15 frames) covered by the image. I go back to frame 1 and resized it to 25% using the transform panel. Now, using math I realized it would be better to have 16 frames for this project, becuase i want it to get bigger over the course of the 15 frames. (It would then be 5% more each step... pretty simple ) Now I figure this can probably be done with some actionscript (i know php very well and I use javascript alot) but I don't know enough about it yet to do it. So I was gonna do it by hand. Presumable a longer and more agonizing task but doable none-the-less. Now I started increasing the image size by 5% per frame and I got to 8 and my program locks up!!! I had just saved, so I redo 5-8 or so and it does it AGAIN.

why would it do this? it's probably not the computer. It's a 2.8ghz with 512 ddr ram, so I'm not sure what's going on. I have now managed to save it on frame 8 where it's locking up but everytime I load up that movie clip to edit and click on that frame and that frame ONLY, it locks right up and stops responding.

any help's appreciate, i'm lost