I'm using Ubuntu 12.10 with Xfce 4.10 and GDM. If I try to log in and get my password right, it logs me in just fine. If I accidentally mistype my password, I get "Authentication failure", which is expected. However, if I mistype my password and then go back and type my password in correctly, a green check mark appears next to my name in the login screen with the words "currently logged in", and it doesn't log me in. I have to restart my computer before I can log in.

Any help would be appreciated. Please let me know if you require more information.