1.- Download 32 bits tar.gz for Linux in Adobe flashplayer website.
2.- Extract in graphic mode the tar.gz file, you will get some different files, delete all except libflashplayer.so and place it in the Desktop
3.- Open a root terminal (inside Knoppix menu). And type: cd /usr/lib/chromium/plugins
4.- Then type: mv /home/knoppix/Desktop/libflashplayer.so .
5.- Done

I went to adobe flashplayer website and I could see the clouds moving (telling me that flash was correctly installed)