Ubuntu :: Nothing Appeared After Login?

I use ubuntu 10.10 Last night when I use my laptop I hangs and when I shut it down the last thing I see is there's a not responding app called at-spi register (or at-sys or something I don't really remember) and the next time I log in to my account there's only login sound heard and the wallpaper I set before, and the mouse cursor. There's nothing else. No nautilus, no panels, nothing. Nothing happened when I press alt-f2, ctrl alt L, etc. There's even nothing happened when I press the power button (unless if I press it a long time it will shut down). the only thing I can do (that I know) is press ctrl-alt f1 & ctrl-alt-f7 to change to tty. And only through tty and recovery mode I can access my account. I decide to create new account using adduser and I can login into the new account successfully. but then again in my new account I can't access all the data from my original account. and I can't use root or sudo command in my new account.

I've tried to reset gnome and nautilus using rm -rf but apparently nothing appeared but login sound, wallpaper (that change to default ubuntu maverick wallpaper), and a mouse cursor that can't do anything.