Mozilla Software Security Device

[koko]

Greetings:  While tinkering with Mozilla I find that one of my websites 
prompts for "Please enter master password for software security device"  
every time I try to get in.  I have searched HELP, looked under ADVANCED 
in Internet Options and it appears to be looking for a Smart Card or 
something. I don't have anything like that.  Maybe it has to do with 
verifying certificates.  I don't know and I can't seem to find out.  
Anybody know?   Thanks in advance.