Completely baffled - snow

Could someone out there solve this? I am trying to build the snow tutorial featured on this site for Flash MX 2004 and it is driving me nuts, nuts, nuts. I copied it exactly from the tut. but every time I test it my machine tells me that it is causing the machine to run too slowly and do I want to abort it. The example featured in the tutorial runs fine - same script, mc’s and background.