HELP NEEDED..preloader not loading at all

Hi there

I have a clip with a percent preloader and as a single base movie its preloader works just fine but if i use this same file as an external swf (+ preloader) to be loaded into a containerMC [without pressig a button] with this action script

_root.containerMC.loadMovie("content.swf");
stopAllSounds();

placed on the main timeline of the base swf the preloader does not work … The swf can be displayed anyway but the preloader dont work at all, I cant figure out why ? I tryed to change the preloader´s code on that file like “_root. to this.” but noops it does not work as well. I´d like to get this preloader displaying the percent loaded from the external swf. Please note that i have a generic preloader and a containerMC on main timeline and this ones are working perfectly, loading all the external files just fine into my containerMC when a button is pressed … So what´s wrong with the other preloader !!! See, i´m new to flash MX and I´m spending hours and hours with this problem and i´m almost ready to give it up…

I will apreciate any help
Thank you very much,