Mac and pc players

hello,
i’ve been developing flash websites on my G5 imac, and for some reason when i play them in either safari or explorer, they usually tend to be on the choppy side, even with a preloader and ultra high speed connection. I have always noticed a significant difference in speed and fluidity between the player in flash and testing it in a browser, but, i recently i tried them out on an oldish dell desktop with dial up connection and to my surprise found it to be considerebly quicker and smoother than even within the flash player.
is there some plugin missing i am missing for my flash player, or am i going about making my sites the wrong way.
heres an example of my own site http://www.ckwebsolutions.com , which works consderably better on pcs than on macs.
please help save me from this frustration,
thanks
jon