Iceweasel: Failure to add security exception

[Johannes Graumann <johannes_graumann@web.de>]

Hello,

When connecting to my home-server (using a self-signed certificate) I 
unsurprisingly get the famous "sec_error_unknown_issuer" error. I now 
navigate to "Edit->Preference->Advanced->Encryption->View Certificates-
>Servers->Add Exception",type in my URL and hit "Get certificate" ... which 
fails with the same "sec_error_unknown_issuer" error seen from the "normal" 
browser window. In brief I'm being prevented to add an exception by the 
cause of the need to add an exception ... or some such. What's going on 
here?

Thanks for any hints, Joh