you can try this method if you want ::
open a terminal and type(or copy and paste) ::
cd ~
wget
http://fpdownload.macromedia.com/get...7_linux.tar.gz
tar -xf install_flash_player_7_linux.tar.gz
cd install_flash_player_7_linux
./flashplayer-installer
press Enter
press Enter
close and exit your firefox first ...
if you only got firefox then press y
or
if you got more than one web browser installed then press m
//note :: seems that this method works ok on my system ...
.