Depending on how your movie is constructed you have a few options.
First, are all the images placed in a frame on the main timeline (this is the least efficient means of displaying the images) or are they loaded at various points along the timeline?
If the images are all placed directly on the timeline, you are basically dealing with the sum of the file sizes of all the different images. To reduce the file size of the .swf, you’ll need to reduce the file size of each individual file. That really comes down to reducing the resolution (and unfortunately the quality) or reducing the physical size and maintaining the resolution.
For example, lets say you have 400 X 300 pixel image at 100% quality. Reduce that to 80% (and lose some quality) or maintain 100% quality but reduce the physical size to 320 X 240.
Also be sure to resize all images to the exact dimensions used on the stage before importing into the library. Don’t bring in an image and then scale it down inside Flash. It still loads the large size file.
You could also construct the movie in such a way that none of the images are loaded until they are needed on the stage. This way, the basic .swf can be just a few kb, and loads really fast. Viewer sees the background or whatever is on the stage with no images yet, then in frame 2 or whatever, use a loadMovie to call in an image or ever another .swf, which could hold the first portion of the movie, 200kb or so. Then after that plays the next section loads, alpha 0 in a few frames before actually needed, then alpha at 100 when needed.
The idea being to spread out the loading time (if you want to keep it at 763K.
Is this movie an animation, with the images morphing and changing shape, or is it more like a slide show, showing one image after another? At 763KB you must have a whole lot of .gifs or they must be pretty big each. Using a custom color palette may reduce size a little but may have some color distortion on some viewers machines.
Slide shows of course could have all images loaded one at a time, via xml. This would really spread out the loading and avoid that one big file.
Hope some of this has helped.
Eye for Video