Firefox Acroread plugin not working

[Chris Lale <chrislale@untrammelled.co.uk>]

I cannot view PDFs using Firefox in Etch (Testing). I get:

   "There was an error while loading the plugin - ewh.api. The plugin 
failed to initialize."

I have these packages installed:

   acroread 7.0.5-0.0
   mozilla-acroread 7.0.5-0.0

According to http://plugindoc.mozdev.org/linux.html#Acrobat:
   Adobe Reader    Version: 7.0.5

  1. Install Adobe Reader.
  2. Create a symbolic link to nppdf.so to your Mozilla plugins directory.
  3. Ensure a copy of acroread is in your PATH.

On my system:
2. /usr/lib/mozilla-firefox/pluginsnppdf.so is a symlink to 
/usr/lib/Adobe/Acrobat7.0/Browser/intellinux/nppdf.so
3. Acroread is in my path since I can launch it from a terminal window 
with the command 'acroread'.

According to Acroread Help -> About Adobe Plugins, ewh is loaded. There 
is a note to say that that the Netscape plugin is required for loading 
(this seems to be the nppdf.so file above).

Any suggestions?
Chris.