Legit swf size using dynamic AS'ing

hi. built a flash ad in cs3. it dynamically calls all images that are located on my server. all the images are animated in actionscript, not on the timeline. the swf ended up being 21K (i’m limited to 40K).

however, it is believed that even though those images live on my server, that when the ad is served, the swf weight is still heavier than the indicated 21K. do the images being pulled dynamically thru the swf still ‘weigh down’ a browser load time?

can that be determined? does that make sense?