Cannot get Mozilla extensions to install

[bfd <bfd@xxxxxxxxxx>]

Hello,

I am having problems getting any xpi extension to install and run as a 
user under Fedora FC2 and Mozilla 1.7.

When I try to install it as a user, either by using the link on the 
extension's site or by downloading the file and opening it in the 
browser, the installation window never appears and nothing is changed on 
the browser windows.

However, the extension will usually install and run as advertised if I 
run the browser as the root user.

Any ideas?

Thanx.