When logging in, screen flashes then kicks back to login screen - Cannot login even in Safe mode I know this is similar to another post here but it went unanswered.
Previous Thread

I have a Late 2010 13" Macbook Air with Mavericks installed since launch.

I was trying to use an external monitor which was giving me fits.  I unplugged it and ended up getting logged out of my user account.  When logging back in my screen turned a bluish tint then flashed and returned to the login screen.  At the time I also had a keychain problem pop up which I was able to fix.  I have tried the suggestions on the other thread other than transferring the information to a new user account as this happened yesterday.

I need to know if anyone has found a fix for this as the previous poster hasn't returned to the thread.  This is my work computer so I need to salvage as much as possible and hopefully fix it completely.

Thank you for any help!
I'm having the identical problem. There appears to be no solution other than to reinstall OSX from the ground up!