I have 11.04 installed in my computer, and I decided to install 12.04 from CD in a new partition, but having only one /home partition shared by both systems.
Installation went ok, but when I enter my password the screen turns black and returns to the login screen half a second later.
I can log in as guest. I can also login at the cmd prompt (going to tty with Alt+Ctrl+F1) with my normal user credentials. When logged in as guest I can also install programs using my normal account password.
LinuxIsMyFriend had the same issue, and he answered the issue himself saying
When I created my new user (with the same name as the old one) I got the correct home directory but wrong UID and GID. When I changed it to the correct values everything worked again!
I'd like to do what LinuxIsMyFriend did, but I do not how. My question is, what should I do to set the proper UID and GID in the 12.04 install?