Can't open user--error message: can't write bytes broken pipe

I installed 12.04 yesterday. I created an admin account and user account. This morning I backed up the user account from the admin account using LuckyBackup as a supersuser, then I did a restore to check it. When I logged out of the admin account and tried to use my user account I got the error message "can't write bytes broken pipe" and got sent back to the user list sign in screen.
I then tried logging into my admin account which worked. So I tried to switch users to the user account. I got a black screen with a blinking cursor and then it went back to the sign in screen.
I can't get to my regular email or any of the work I was doing.