Safari 6 in Mountain Lion

Question

Having upgraded to Mountain Lion, I am having  problems using Safari 6.  I'm unable to load up quite a few pages (including the apple discussion forum), I'm getting the 'can't establish a secure connection'. I have no parental settings turned on, I've emptied the cache, cleaned the cookies and reset safari, all to no avail, any suggestions?
Also, Safari 6 appears to be hanging when loading up certain pages as well...
Again, suggestions welcome? Otherwise I'll reluctantly revert back to Firefox.
Thanks.

Answer 1

My observations are as follows:
The problem is specific to Safari.  I can use Chrome without any problems (including Rapport).
It is intermittent and I can usually clear it by closing and then restarting Safari.  I suspect this is what gives the appearance of a "fix" when either Rapport is upgraded or disk utility is used to repair permissions.
I have tried turning Rapport off and the problem returns. 
There is no discernible pattern to when sites are blocked or allowed through. Sometimes it works for one site and then the same location is blocked at a later time.  The common feature is all the sites are "secure".
I notice that Safari is looking for site based security certificates and it sometimes reports these are not recognised - even from well known providers.
My conclusion is that the latest version of Apple's browser is not up to specification and is, in some way, mis-matched by OS X10.8.  Reluctantly, I shall switch to either Firefox or Chrome until someone at Apple comes up with a fix that works.  Surely, this should have been fixed pre-release?  At least I then have the security of a browser that works and where it isn't necessary to spend hours trying to identify fixes which second guess flaws created by the software providers.
Many good and helpful contributions from people.  Good to know others are in the same position.
Regards to all