First check your extension names it most be ".w3d" and not
".W3D" or ".w3D". Second your shockwave 3d files must to be on a
folder called "dswMedia" for security reasons on the server. Any
external file you need for your movie online most to be there.
At last, before you send any command to your loaded .w3d file
inside your movie be shure to check it´s member estate, if you
tray to do something with it and isn´t ready this generate
problems or simply does nothing halting your movie.