My Firefox suddenly have stopped loading some websites properly. For example, twitter.com or mozilla.org. Some pages won't load completely and I get this "Secure Connection Failed" note: Secure Connection Failed An error occurred during a connection to www.mozilla.org. The OCSP response is not yet valid (contains a date in the future). (Error code: sec_error_ocsp_future_response) The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. Other (e.g. twitter) sites open only as a text (or html), which looks like no style sheets being applied. I've reset the program to defaults like shown here http://ccm.net/faq/1154-how-to-reset-firefox-to-default-settings, manually deleted "Profile Folder" (about:support > Application Basics > Profile Folder) but the problem remains. I have no anti-virus program installed on my system. I have my Windows Firewall disabled (just in case). I also tried to rename the firefox.exe program file to see if that has effect.. well it hasn't. And, btw, my other browsers work just fine at the moment. Would appreciate any help and suggestions. Thank you!