Description of problem:
Upon going to a secure web site, Firefox throws an error.

Version-Release number of selected component (if applicable):
firefox-1.5.0.6-2.fc5.i386.rpm

How reproducible:
Every time, but not everyone experiences it.

Steps to Reproduce:
For me, it's enough to update Firefox to 1.5.0.6 and go to a https: site.
  
Actual results:
Unexpected response from server
Firefox doesn't know how to communicate with the server.
* Check to make sure your system has the Personal Security Manager
installed.
* This might be due to a non-standard configuration on the server.

Additional info:
I upgraded directly from version that came with FC5, if that's relevant. This
din't start happening immediately after upgrade, but after two or three visited
websites.