My firefox does the same thing. i used to be able to play them but now it keeps saying I have to update my shockwave, but its already updated. An easy fix I found was just open the game through chrome, it works and you might already have it installed.
wow wow wow Watch Out
Don't Be So Quick To Update Shockwave , Flash or Java
There is a new virus going around the internet, the Flash Virus (as it's been called) it pops up a website with a message box telling you to update flash or java or shockwave, than you poor souls click update, and your actually installing a bunch of malware on your computer, your not even getting the advertised update, I found out about it when I clicked Ok to quick I looked at the address bar and noticed it wasn't from Adobe, but it was to late.
Be careful when you update. Dont update Java, Flash or Shockwave from any popup window that you were not expecting, any website in another language other than english, any website that mentions HD videos on it or and website with that starts with anything other than get.adobe.com/flashplayer http:// as always.