I find that if you have acroread on board, and the plugin/addon enabled and clear your private data, when you exit firefox the plugin comes back to life.
As a result I've deleted the /usr/lib/mozilla/ plugin for acroread. I prefer to save the pdf and view it, rather than read it in the browser. This issue was a pita.
Last edited by Old_Fogie; 01-30-2012 at 08:19 PM.
Reason: I had a moment and typed like 'carp'