Cannot install Adobe Shockwave Player on Mac

Hi.
Installation of Adobe Shockwave Player (ASP) on my Mac OSX 10.6 Snow Leopard always fails. Maybe they are not compatible with each other? Tried reinstalling the client, but got the same outcome. Also tried different versions of ASP, but the results were the same.

Error:
Install Adobe Shockwave 11.5
There were errors with the installation. You may want to try installing
again.
The installation failed.
The Installer encountered an error that caused the
installation to fail. Contact the software manufacturer
for assistance.
Please help me fix the problem. I want to attend the BrainFitness test as soon as possible. Thanks.
