Here is how I managed to see flash movies in my firefox(64-bit version).
You dont need to install the 32-bit version of Firefox!!!!!!
Just do the followings.
1st
Open YaST2.(If u do not understand i cant help u)
2nd
Check if the gtk2 and tha gtk2-32bit are installed. If they are not install them.
3rd
Check if the nspluginwrapper is installed. If it isnt install it.
4th
Search for Macromedia Flash Plugin(key word "flash"). Install it.
5th
Close YaST2 and open a terminal(console).
6th
sudo -s
hit enter
root password
hit enter
7th
cp /usr/lib/browser-plugins/libflashplayer.so /usr/lib64/firefox/plugins
hit enter
8th
nspluginwrapper -i /usr/lib64/firefox/plugins/libflashplayer.so
hit enter
9th
Check if you can see a flash movie.