Thanks David. You can access the SECURE https forum URL? It's possible you have some diff settings in FF prefs than me, for security settings.
Thanks for the link. I understand about over riding the security warning on certs. The "tutorial" on that link is a bit misleading (for those not very familiar w/ site security certificates).
1st, it says, "Now click on the Add Exception. You will see the following screen." (Exception being the operative word)
Then it says, "Here add the site you want to get the certificate to. Then click on get certificate. Firefox will check for the certificate and show it.
Firefox is NOT checking a site for a new, valid certificate on these screens / process. It's simply allowing users to over ride FF's warning that the site certif. has something wrong w/ it.
Do I trust Heidi Forums? Sure. That doesn't mean their certificate doesn't need attention (maybe expired, etc.). It also does NOT mean that (as FF warns) someone hasn't maliciously tampered w/ the connection. In this case, FF is reporting (in details) that Heidi cert's chain of authority is incomplete (which it is, looking at the actual certificate).
Out of all the similar warnings I got for sites I often use, then suddenly get a warning, 98% of the times I've checked w/ the company / webmaster, there WAS a problem w/ the certificate. Usually, the webmaster / IT dept. was "aware & working to fix it." Some of these are BANKS that let their certs expire, etc.
If you are accessing the httpS:// url & getting no warning, then there may be a prob w/ my FF or we have diff prefs settings, - who knows. But I RARELY get such warnings from reputable sites, where there is NOT an actual prob. w/ the cert. So, dunno answer for this one - yet.