I have deb lenny.
I have my firefox (iceweasel) configured and running with plugins.
I also installed opera. I simply copied "libflashplayer.so" of firefox under opera/plugins. I also checked from preferences whether it is known by browser. It is there.

When I open a page with flash, it seems as if the plugin exists, When I take mouse on, it writes:
"click to activate and use this control"
but it cannot be click, and nothing changes when it is clicked.

I tried for both adobe's test page and youtube. same.

I had my java and mplayer plugins configured correctly with the same way.

What can I do in order to make my flash plugin work for opera?

What version of Opera are you using? Newest flash has some known issues according to posts on the Opera forums. Try using Build 1709 of Opera 9.5 either static or shared versions available here. The shared .6 version seems to work best for me of all of them, but may not be the same for you. Be sure and do a clean install, ie purge everything, unless you are sure your current Opera profile won't muck things up.

opera --version
Opera 9.25 . Build 687 for Linux. Qt library 3.3.7.

is it too old?

I never could get that version to work well. Go to the website I gave you above and download 1709. It is 9.5 beta 2 version. but until yesterday, it was the only one I've gotten to work on Etch or Lenny. Or there was a new beta release yesterday 1737 that also works very well for me. They are betas though so beware - read the warnings about data/mail loss etc... I haven't had any trouble but...they are betas.

thanks for all. I'll try it.

Easier to just add it to your sources.list that way you always have the current.

# Opera Browser - Production release
#deb http://deb.opera.com/opera/ stable non-free
#deb http://deb.opera.com/opera/ testing non-free
#deb http://deb.opera.com/opera/ unstable non-free
# Opera Browser - Beta release
#deb http://deb.opera.com/opera-beta/ stable non-free
#deb http://deb.opera.com/opera-beta/ testing non-free
#deb http://deb.opera.com/opera-beta/ unstable non-free

The betas tend to work better with Flash.

Actually I had better luck dloading from the Opera site and using dpkg - but I am sure that is just me.

thank you so much. It works now. I upgraded to 9.50 beta.

Good for you! You're welcome.