Hello.

So, to be clear, I'm running debian lenny on AMD64. I installed the flashplayer-mozilla package (installs 32-bit plugin), and the nspluginwrapper package. I then ran "nspluginwrapper -i /usr/lib/mozilla/plugin/libflashplayer.so", and re-scanned for plugins in konqueror.

So, now, when I visit a page in iceweasle, I can view flash animations without any problems whatsoever.

In konqueror, however, any page with a flash animation simply shows "klash: stop playing" in the status bar. (klash is a flash player for KDE; it is NOT INSTALLED)

Konqueror's plugin page lists the nswrapper-libflashplayer.so as a plugin.

Does anyone know a solution?

Did you set nsplugins as your primary flash viewer?
I had the same problem and heres what I did (in Xubuntu Fiesty, though the steps should be the same)

In Konqueror, go to Settings -> Configure Konqueror.
Select 'File Association' from the left-hand menu.
In the text box, input "swf", and you'll notice that only the 'applications' list will remain.
Expanding 'applications' should show you something along the lines of 'x-shockwave-flash', select it.
Some new things should appear on the right-side, showing two tabs (General and Embedding). Select the Embedding tab.
In the Embedding tab, you'll notice Klash and Netscape Plugin Viewer (nsplugin). Select the Netscape Plugin Viewer and Move it up to the top of the list (via the "Move Up" button right next to it)

That should do it... I hope >.<"

That solved the problem wonderfully.

It hadn't occurred to me to check file associations (I expected the absence of klash would leave nspluginwrapper the only option).

Thanks!