Make sure that time and date are set correctly.
If the suggestions made in these articles do not help, contact Apple.
Sorry that suggestions in the article did not help.
Now you mave to contact Apple or take the computer to the Apple store to have it checked out.
Before that try SMC reset.
Reset SMC. http://support.apple.com/kb/HT3964
Choose the method for:
"Resetting SMC on portables with a battery you should not remove on your own".