On-going problems with flashplugin for IW

[AG <computing.account@googlemail.com>]

Hello all

In Iceape and other browsers (e.g. Opera) I can watch embedded 
(streaming?) videos on-line.  In Iceweasel/ Swiftfox I cannot.  Insterad 
I get a variation on this message: "Note: Either you do not have Adobe 
Flash Player installed on your computer or your Flash Version is 
outdated. You need Flash Player in order to view this item. Download 
Flash Player now. <http://www.macromedia.com/go/getflashplayer>"

I have double-checked and I have the latest flashplugin-nonfree 
installed and seems to be accessible to the other browsers, so why 
doesn't IW "see" the plugin and use it as well?  In my 
~.mozilla/plugins/ directory the library libflashplayer.so is installed 
and executable and as far as I can tell, the plugins are registered with 
IW as seen by doing about:plugins in the address bar.

A search using Google only keeps showing me the same darn resolution - 
install the nonfree plugin and check that it is in the about:plugins.

Now what?  Any help on this please as it is puzzling and irritating.

Thanks

AG