Upload? Download? Or you mean it is really slow in loading? Can you please provide the link to your site?
1.) Can you provide a link?
2.) Did you use a preloader?
3.) AS2 or AS3?
4.) What is the file size of your SWF file?
Uhm CS3 is the IDE. AS2 or AS3? If you are using AS2, you can implement a preloader using the MovieClipLoader Class. If you are using AS3, you can implement it using the Loader Class. Google about how to use those classes. 700kb is relatively big to load into a browser so it is recommended you have a preloader for users to see the loading progress.
Ok, I think this is getting a bit over my head...I'm in AS3 (action script 3) but is there a way to maybe compress my file more? my backgroudn image is 72 dpi, I have compress movie checked when saving and I even tried lowering the JPG Quality on the flash movie, which I don't see any difference and the file size didn't change either...I tried to googlng Loader Class with very confusing results. Is there a good website for flash dummies?
If you just have one SWF file, then you might want to try this tutorial http://www.republicofcode.com/tutorials/flash/as3preloader/
Basically, you will be monitoring the bytesLoaded of bytesTotal
var total:Number = this.stage.loaderInfo.bytesTotal;
var loaded:Number = this.stage.loaderInfo.bytesLoaded;
Or try to search other tutorials with keywords "preloader" and "AS3". If you encounter any problems, feel free to ask.