Rugged Audio Shield for Arduino

Hello everyone!
I am a newbie in the Arduino world, having lots of fun, but ran into a problem.
I am trying to combine a Rugged Audio Shield with an Arduino WiFi shield on top of an Arduino Uno.
I got the Audio shield to work by itself, I got the WiFi to work by itself, but when I plug in the 3 of them together, in no matter what order, I keep getting the message "WiFi shield not present" (not sure this is the exact message, but...).
Is there other ways to connect them, or at least how do I diagnose why the WiFi shield stops working when the Audio shield is present?

Appreciate any comments and suggestions!
h