On boot at the password prompt - after I enter my password I get some error popup which disappears too fast to see then it reverts back to same password login Greeter screen. Same screen has icons where I can choose :

Select desktop environment

Cinnamon
GNOME Flashback
Ubuntu

I really want to login to the normal ubuntu 13.10 Unity using above Ubuntu, however I can successfully login using either : Cinnamon or GNOME. Suggestions ? I have researched around and no help after removing file ~/.Xauthority Also I see this :

cat .xsession-errors 
Script for cjkv started at run_im.
Script for default started at run_im.
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd respawning too fast, stopped