This is not a copy & paste problem.

I have a LAMP set-up on my machine. In the past I built my pages,
filled them with text from Ooo and happily continued on my way to a
complete page. This however was disrupted some 6 months or so ago. The
problem was temporary however, a message popped up in Firefox telling
me Firefox had disallowed the action. I work off line, well using
Localhost but Firefox thinks I am On line without a local connection, so
I had to reproduce the effect while at my local hot spot. Firefox asked
if I would like to install the fix that seems to be more of an
intentional security thing, as I understand it. I said yes to the
inquiry, and I was then able to paste into the Firefox browser.

The reason I talk about my LAMP server is the fact that this whole thing
happened on my laptop rather than between two computers as it would be
over the net or something. The fact that it is a localhost connection
means little however, because we are using a web application so security
is handled the same way. Are you getting a request to install a firefox
pluggin as I did? I would guess you are. Please don't ask for more
info, it has been a while and for the life of me I can't remember what
the pluggin was called.