Possible Duplicate:
Appearance does not change on switching the theme
Prorouge :( Naughty Me haz launched unity-greeter (lightdm) on gnome-terminal with processing unity.
I accidentally login with the same user with my single click.
Edit It seems it would be easier to figure it out by graphic:

Then I clicked the box and logged in.
The theme all sessions in the same user account changes like the following:



In my opinion, this maybe a problem of mis-detection of icon-theme? or GTK+ theme? or Shell theme?
Or, worst, the broken behavior of whole system before login
I have try these steps but meaningless ( in my own user ):
- reboot
- unity --reset && reboot
- rm -rf ~/.config/compiz && reboot
- apply theme at System Setting > Appearance and reboot
- reinstall unity-greeter, lightdm
Here are the facts I have found out:
- ugly-themed interface in gnome3-fallback-session, Unity 2D, Unity with the same user
- normal interface in Guest session
- broken shutdown function in whole system EVEN before the broken user has been logged in ( in a new boot up process ).
According to fact#3, I weakly believe everything goes wrong before the broken user has been logged in.
Series of problems are brought out, something like
- unable to unlock user (account) setting with disabled unlock button ( and add & delete button )
- crash in ubuntu software center
Due to the fact that I have found out many 'complication', I believe that I would reinstall the whole system if it cannot be solved by fixing a little but major problem.
Thanks for involvement. :)