Thank you Christian, this finally worked!!
I did not think Firefox would cache even redirects! Technically, it is not part of the site content, it is governed by the .htaccess file which is part of the http server configuration.
And frankly this type of caching seems quite aggressive to me. It could very well bite casual users, too.
BTW, I learned something new today, and finally fixed the behavior of my Firefox (and I'm sure I'll be able to fix Falkon in much the same way).
For those following this thread, you may be interested in knowing how I cleared the contents cache in Firefox.
Hope this helps.
Bye
Cris