Snow tut no worky

sorry guys…im a noob

just learning flash…i was working through the tutorials and got stuck on snow 2.0. i followed all the steps and then when i try to run it i get a warning message saying:

script in thismovie is causing flash player to run slowly. if it continues to run, your computer may become unresponsive. do you want to abort script?

if i dont abort it comes up as a still image.