Anyway, it's not that big a deal and it takes all of five minutes to fix. Herewith are the instructions for installing Flash support for Mozilla.
Personally, I prefer to download the installer manually from the Adobe web site. It comes as a 2.5MB archive file in tar.gz format.
Open up a command-line terminal and unpack it. Note that, by default, Mozilla places all downloaded files in the Desktop.
cd ~/Desktop
tar xzvf install_flash_player_9_linux.tar.gz
Go into the resulting
install_flash_player_9_linux
directory and run the installer.
cd install_flash_player_9_linux.tar.gz
./flashplayer-installer
Follow the dialog. Most defaults should be sufficient. Of course, you'll need to restart your browser to activate the Flash component. You should then be good to go!