Pages Won't Load Properly, Certificate Errors

Question

Ever since upgrading to 4, i have been having problems with images and site loading properly. I am also having problems with the digital certificates, too. I tried going back to an older version but i am still having these problems. I have removed add-ons and without any change, re-added them.
Here are problematic certificates i have:
adversity.googlecode.com:443
secure.fanboy.co.nz:443
easylist-downloads.adblockplus.org:443
static.addons.mozilla.net:443
crash-reports.mozilla.com:443
www.navyfederal.org:443
www.paypalobjects.com:443
I have looked on the forums and on Google without finding any help or useful information.

Answer 1

Do a clean (re-)install:
* Download a fresh Firefox copy and save the file to the desktop.
* Firefox 4.0: http://www.mozilla.com/firefox/all.html
* Firefox 3.6.x: http://www.mozilla.com/en-US/firefox/all-older.html
* Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
* Don't remove personal data if you uninstall the current version.
* It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
* It may not be necessary to create a new profile, so first try if it works with your current profile and if not then create a new profile.
Create a new profile as a test to check if your current profile is causing the problems.<br />
See [[Basic Troubleshooting#Make_a_new_profile|Basic Troubleshooting&#58; Make a new profile]]
There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins"
If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files)
See http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox