Flash player works fine in IE, but not in Mozilla

A big "Q" with a question mark in it desplays in Mozilla whenever Flash Player is required.

I have done all the things I should have - uninstalled and reinstalled flash player, made sure Shockwave was installed, ensured that Quicktime was not set to play Flash files. I have even run the Adobe test and been informed that Flash and Shockwave are both successfully installed. But still, the big Q.

Any ideas???