finish creating movie and discovered something...

[2cxc]

I finish the movie i've been working on and it ranged about 54k published at 78%. I then created the same main stage and imported the swf and published at 80%, and the size shrunk to 45k. Now this amazes me, and i'm wondering what ramifications this will have (good and bad) on the movie, and is it like a ,jpeg picture where each time you save it, it decreases in resolution?

thanks for the info & 4 helping open up a can of worms