How do I make a movie completely load before playing

I am trying to make a flash movie, and so far I have the preloader on the first frame and then the main movie clip on the next frame, but when I watch the movie from the website the preloader loads and then starts playing the movie, but it plays kinda choppy at the beginning it kinda looks like the movie isnt loading before its playing. how can I fix this. Just to add I really dont know much scripting, My animation is mainly motion tweens. IF ANYONE CAN HELP ME FIGURE OUT HOW TO MAKE THE MOVIE PLAY SMOOTHLY I WOULD APPRECIATE IT. here is the link to the .swf (its the NAS animation you initially see). www.nasindependenceday.com

Preloaders do the job for me.

Here’s the tutorial I used: http://www.kirupa.com/developer/flashcs3/preloader_as3_pg1.htm

If you already tried that and it didn’t work, I have no idea. =\

I have a preloader, but for some reason the video is still choppy at the first second. IM STUCK I dont know what else to do. also I have a button on the whole animation that when you click it it brings up home page, but it opens it in a new window,and I need it to open in the same window!?!? any help please