Unity Web Player - Game don't start

Hello!

I try the Facebook game "The wizard of Oz" which needs the Unity Web Player. I installed the newest version but the game don`t start...only the game logo appears. A message with "Unity Player is crashed" appear too, but the message only appear in Chrome not in Firefox...but the game don't start in both browser.

Maybe my PC is too old. I have Windows XP (S3), 2 GHZ (not Dual-Core), 1 GB RAM and a Nvidia Geforce FX 5500. I played games with good 3D-Graphic before like Vindictus Online or Minecraft. :D

So, what is the problem here?

Thanks for any help! :)