If you start receiving an email on your root account from certwatch that looks like this:

 

################# SSL Certificate Warning ################

Certificate for hostname ‘rune.sunaj-home.org’, in file (or by nickname):
/etc/pki/tls/certs/localhost.crt

The certificate needs to be renewed; this can be done
using the ‘genkey’ program.

Browsers will not be able to correctly connect to this
web site using SSL until the certificate is renewed.

##########################################################
Generated by certwatch(1)

 

Then you need to generate a new cert for your system.  The command is  as follows:

openssl req -new -days 365 -x509 -nodes -out /etc/pki/tls/certs/localhost.crt -keyout /etc/pki/tls/private/localhost.key

For more indepth instructions on the procedure, go to this blog, its where I found the info:
http://stevejenkins.com/blog/2010/08/renewing-a-self-signed-ssl-certificate-on-fedoracentos