Can't login. Seems to login and kick me out. Also I don't see the secondary account on the greeter.

[Ivan Rivero Alonso]

Started since a few weeks after I started switching from 2 monitors to 1 and viceversa (working environment and home env.). Might be just a coincidence.
Last three times, I've got dropped into the command line.
First time, I reboot and It worked normally.
Second, I had to startx from command line. It worked with problems. I rebooted and worked well.
Today it didn't go through, so I started on failsafe mode and reconfigure packages. It removed unused 3 packages. Unfortunately I didn't see which ones.
After that, I starts X system, but on greeter I can't see the second account (primary, secondary, guest) and trying to login, it goes black come back to greeter like nothing happened. No wrong password, just like restarting.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lightdm 1.2.3-0ubuntu2.4
ProcVersionSignature: Ubuntu 3.2.0-63.95-generic 3.2.57
Uname: Linux 3.2.0-63-generic x86_64
NonfreeKernelModules: nvidia wl
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Mon Jun 16 11:16:18 2014
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_CA:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[Ivan Rivero Alonso (riverinyo)]

I deleted /home/myuser/.Xauthority and it got back to normal.

[Ivan Rivero Alonso (riverinyo)]

I started this morning with the second monitor plugged but off.
This action dropped me to the command line.
On restart (secondary monitor on) it went back to normal.
Hope it helps.