Firefox plugins - can't get 3.6.13 to see plugins at all.

[Chris G]

I'm having big problems with Firefox (3.6.13) on Ubuntu 10.04.  It
simply refuses to see any plugins at all.

In addition the "Open Contianing Folder" button on the Troubleshooting
Information page does nothing, I suspect this may be conencted with the
plugins problem.

I have no pluginreg.dat file anywhere in my home directory.

All in all Firefox seems to want to ignore plugins completely!

Any ideas how to get a plugin to install?

-- 
Chris Green