Sound glitch in flash cs4

anyone that has done a preloader and has sounds in your site they came to find out that in order for the preloader to start at 0% you need to uncheck the option to export sound in the first frame, for some reason i am using a preloader using as2 in flash cs4 and since the option to export on the first frame is uncheck the sound does not play.

if i check that box then the preloaders shows up after the music is loaded (meaning the preloader starts at 20% and not 0%) and not before… any ideas about this…???

thanks in advance.