This is "slim" installer and it is almost guaranteed to download other components from within the plugin itself creating issues all the time.

If you are interested in shockwave and use it frequently,I suggest this full version which you can pick from the form below (it is drop down form, doesn't ask for mail or anything)

http://get.adobe.com/shockwave/otherversions/

Careful about CPU/Arch choice and picking "Safari" or "Firefox" has NO difference at all, OS X uses a central place for plugins, come on Adobe people!