Firefox - Plugger error
 

I have just upgraded firefox from 0.9 to 0.9.1 using the tar.gz in Slackware9.1. I have followed the README instructions and executed as root first and then closed it down and launched as a user. The brower is working fine (using it now ;) ) but on both occasions the following message is output in the shell:

*** loading the extensions datasource
Plugger: Unable to find pluggerrc file!
LoadPlugin: failed to initialize shared library /usr/lib/mozilla-firefox0.9.1/plugins/rpnp.so [/usr/lib/mozilla-firefox0.9.1/plugins/rpnp.so: undefined symbol: __pure_virtual]

I have /usr/lib/mozilla-firefox0.9.1/plugins/plugger.so but no pluggerrc. Where should that be?

What does the [/usr/lib/mozilla-firefox0.9.1/plugins/rpnp.so: undefined symbol: __pure_virtual] mean?

Thanks