This started with me adding a graphics card to my system. When I booted up, ubuntu complained that the graphics config had changed, and gave me a terminal session. I copied /etc/X11/xorg.conf.failsafe to xorg.conf, and that gave me the standard graphical login manager.
Nw, when I try to log in the screen goes blank for a second, then returns me to the login manager. It tells me when I give it a deliberately bad password, so I know I'm authenticating. When I go across to a virtual terminal, I find that nothing in my homedir has been modified, except for ~/.dmrc if I've tried a different login mode. rAs a result, my usual resort of consulting ~/.xsession-errors is unavailable.
Other accounts like "Guest Session" are able to log in without problems, just mine fails. I have tried moving my ~/.xsession and ~/.xsessionrc to ~/xsession{,.rc}.bak, no effect. I've looked at /var/log/{syslog,auth.log,kern.log,Xorg.0.log}, and nothing interesting appears there when I try to log in... I've tried all the suggestions in the following earlier questions:
Login returns to login screen Where should I look to diagnose login freezing? Can't log in to ubuntu 12.04
What else can I try to diagnose this?
I think for now, I am going to work from a different account, but that is going to be a bit of a hassle.
