Unrecognized security certificate warning is gone

[Marc Shapiro <marcnshap@gmail.com>]

I am using Firefox, not Iceweasel, but I think this question should 
apply in either case.  I am trying to connect to work using the Citrix 
client.  I used to get a warning that the certificate was not recognized 
and do I want to continue, or not.  I am no longer getting the warning, 
but Firefox is assuming that I have said NOT to accept the certificate 
and it is closing the connection.  How do I get the warning and question 
back.

BTW, this is happening with Opera and Kazehakase, as well, not just 
Firefox.  Is there some place that all of these browsers would look to 
define this behavior?

Marc