[LightDM] lightdm sometimes kicks me out after autologin

[Bruno Dantas]

I hope one of you lightdm gurus can help me. I use Arch GNU/Linux and have always used lightdm with autologin without any problems. With the two latest versions of lightdm that I've had on my system (1:1.4.0-3 and 1:1.14.2-1), sometimes lightdm will kick me out of my desktop to its graphical login screen immediately after autologin. For some strange reason, this only seems to happen on the first boot of each day--on subsequent boots, autologin works just fine.

I've asked about this on the Arch forums, but have gotten nowhere.

I am a member of the autologin group. My desktop environment is MATE 1.10 in case it matters. Here are some files you may want to see:

1) /etc/lightdm/lightdm.conf: 
https://www.dropbox.com/s/pnrizngv5kez6j9/lightdm.conf?dl=0

2) /var/log/lightdm/lightdm.log (from today's first boot, when lightdm kicked me out after autologin):
https://www.dropbox.com/s/yrfmdodgyzy7n46/lightdm.log%20%28kicked%20out%29?dl=0

3) /var/log/lightdm/lightdm.log (from today's second boot, when autologin worked perfectly):
https://www.dropbox.com/s/6uacmtnqnhosa0a/lightdm.log%20%28normal%29?dl=0

My computer is perfectly usable, but it bugs me a lot when it doesn't behave as expected. Any help would be greatly appreciated.

Thanks,
Bruno